Prospectus Supplement

                               Dated Oct. 3, 2005*

        RiverSource(SM) New Dimensions Fund(R) (Oct. 3, 2005) S-6440-99 Y

SEPARATION FROM AMERICAN EXPRESS COMPANY

On Sept. 30, 2005, Ameriprise Financial, Inc. (Ameriprise Financial)
became an independent company with no affiliation to American Express
Company and is  now trading as a separate public company under the ticker
symbol AMP.  Ameriprise Financial and its subsidiaries provide a variety
of services to the RiverSource Mutual Funds:



- -------------------------------------------- ------------------------------------------- -------------------------------------
Company Name (Effective Aug. 1, 2005)         Former Name/Service Provider                Services
- -------------------------------------------- ------------------------------------------- -------------------------------------
                                                                                   
Ameriprise Financial, Inc.                   American Express Financial Corporation      Administrative Services
- -------------------------------------------- ------------------------------------------- -------------------------------------
RiverSource Investments, LLC                 Services previously provided by American    Investment Management Services
                                             Express Financial Corporation
- -------------------------------------------- ------------------------------------------- -------------------------------------
Ameriprise Financial Services, Inc.          American Express Financial Advisors Inc.    Distribution Services
- -------------------------------------------- ------------------------------------------- -------------------------------------
RiverSource Service Corporation              American Express Client Service             Transfer Agent Services
                                             Corporation
- -------------------------------------------- ------------------------------------------- -------------------------------------
Ameriprise Trust Company                     American Express Trust Company              Custodian Services
- -------------------------------------------- ------------------------------------------- -------------------------------------


On Oct. 1, 2005, the Fund changed its name from AXP New Dimensions Fund
to RiverSource New Dimensions Fund.

ADDITIONAL UPDATE

At a Board of Directors meeting on January 12-13, 2005, the directors of the
Fund determined that it was in the best interests of shareholders to withdraw
the Fund's assets from the master portfolio structure. The steps to withdraw
from the master portfolio and establish an independent portfolio of securities
for the Fund are expected to be completed in late 2005 or early 2006.
RiverSource Investments, LLC, the investment manager to the master portfolio,
will continue to serve as investment manager to the Fund under the same terms
and conditions.

S-6440-25 A (10/05)

Valid until next update.

* Destroy Oct. 17, 2005


The fees and expenses table and expense examples contained in the Fund's
prospectus, which describe the fees and expenses you may pay if you buy and hold
shares of the Fund, have been updated, adjusted to reflect current fees. The
updated fees and expenses table and expenses examples referenced below replaces
those in the Fund's current prospectus.

FEES AND EXPENSES

Fund investors pay various expenses. The table below describes the fees and
expenses that you may pay if you buy and hold shares of the Fund. Expenses are
based on the Fund's most recent fiscal year, adjusted to reflect current fees.



Shareholder Fees (fees paid directly from your investment)
                                                               Class A       Class B      Class C      Class Y
Maximum sales charge (load) imposed on purchases(a)
                                                                                            
(as a percentage of offering price)                             5.75%         none         none         none

Maximum deferred sales charge (load) imposed on sales
(as a percentage of offering price at time of purchase)         none(b)        5%           1%          none


Annual Fund Operating Expenses(c) (expenses that are deducted from Fund
assets)

As a percentage of average daily net assets:  Class A  Class B Class C  Class Y
Management fees(d)                             0.45%    0.45%   0.45%    0.45%
Distribution (12b-1) fees                      0.25%    1.00%   1.00%    0.00%
Other expenses(e)                              0.26%    0.29%   0.29%    0.34%
Total                                          0.96%    1.74%   1.74%    0.79%

(a)  This charge may be reduced depending on the value of your total investments
     in RiverSource funds. See "Sales Charges."

(b)  For Class A purchases over $1,000,000 on which no sales charge is assessed,
     a 1% sales charge may apply if you sell your shares within one year after
     purchase.

(c)  Both in this table and the following example Fund operating expenses
     include expenses charged by both the Fund and its Portfolio as described
     under "Fund Management and Compensation."

(d)  Includes the impact of a performance incentive adjustment fee that
     decreased the management fee by 0.07% for the most recent fiscal year. The
     index against which the Fund's performance is measured for purposes of
     determining the performance incentive adjustment is the Lipper Large-Cap
     Growth Funds Index. See "Fund Management and Compensation" for more
     information.

(e)  Other expenses include an administrative services fee, a transfer agency
     fee, a custody fee and other nonadvisory expenses and, for Class Y shares,
     a shareholder service fee.

                                    -- 2 --



Examples

These examples are intended to help you compare the cost of investing in the
Fund with the cost of investing in other mutual funds.

These examples assume that you invest $10,000 in the Fund for the time periods
indicated and then redeem all of your shares at the end of those periods. These
examples also assume that your investment has a 5% return each year and that the
Fund's operating expenses remain the same. Although your actual costs may be
higher or lower, based on these assumptions your costs would be:

                               1 year      3 years      5 years     10 years
Class A(a)                      $667         $863       $1,076       $1,690
Class B                         $677(b)      $948(b)    $1,145(b)    $1,850(c)
Class C                         $277(b)      $548       $  945       $2,057
Class Y                         $ 81         $253       $  440       $  982

(a)  Includes a 5.75% sales charge.

(b)  Includes the applicable CDSC.

(c)  Based on conversion of Class B shares to Class A shares in the ninth year
     of ownership.

You would pay the following expenses if you did not redeem your shares:

                               1 year      3 years      5 years     10 years
Class A(a)                      $667         $863       $1,076       $1,690
Class B                         $177         $548       $  945       $1,850(b)
Class C                         $177         $548       $  945       $2,057
Class Y                         $ 81         $253       $  440       $  982

(a)  Includes a 5.75% sales charge.

(b)  Based on conversion of Class B shares to Class A shares in the ninth year
     of ownership.

                                    -- 3 --


The Fund's Board of Directors has approved in principle the merger of
RiverSource New Dimensions Fund into RiverSource Large Cap Equity Fund (formerly
AXP Large Cap Equity Fund).

Completion of the merger is subject to a number of conditions, including final
approval by the Board and approval by shareholders of RiverSource New Dimensions
Fund. It is currently anticipated that, pending final approval from the Board,
proxy materials regarding the merger will be distributed to shareholders during
the fourth quarter of 2005, and that a meeting of shareholders to consider the
merger will be scheduled for the first quarter of 2006.

Effective Oct. 17, 2005, the Fund's "Principal Investment Strategies and
Principal Risks" sections are revised as follows:

Under normal market conditions, at least 80% of the Fund's net assets are
invested in equity securities of companies with a market capitalization greater
than $5 billion at the time of purchase. The Fund may invest in income-producing
equity securities, such as dividend paying stocks, convertible securities and
preferred stocks. The Fund will provide shareholders with at least 60 days'
notice of any change in the 80% policy.

In pursuit of the Fund's objective, the investment manager (RiverSource
Investments, LLC) will hold both growth and value companies and at times may
favor one more than the other based on available opportunities.

When optimizing for growth, the investment manager invests in companies it
believes to have above-average long-term growth potential, or technological
superiority, and it selects investments based, among other factors, on:

   o Effective management.

   o Financial strength.

   o Competitive market or product position.

   o Technological advantage relative to other companies.

                                    -- 4 --


When optimizing for value, the investment manager invests in companies that
appear to be undervalued by various measures or that may be temporarily out of
favor, but have good prospects for capital appreciation, and it selects
investments based, among other factors, on:

o  Identifying a variety of large, well-established companies whose underlying
   fundamentals are stable, or are anticipated to become stable, or whose
   fundamentals are improving.

o  Identifying stocks that are undervalued:

   o because they have one or more ratios, such as price-to-earnings or
     price-to-cash flow, that are low relative to the general market, or have a
     yield that exceeds the market,

   o because one or more of their valuation ratios are low relative to
     historical levels for the stock,

   o because one or more of their valuation ratios or other financial measures
     make that stock attractive relative to its peers, or

   o because they are undervalued relative to their intrinsic value, as
     identified by the investment manager.

In evaluating whether to sell a security, the investment manager considers
factors including, among others whether:

o  The security is overvalued relative to other potential investments.

o  The security has reached the investment manager's price objective.

o  The company has met the investment manager's earnings and/or growth
   expectations.

o  Potential losses due to factors such as a market down-turn, can be minimized.

o  A more attractive opportunity has been identified.

                                    -- 5 --


PRINCIPAL RISKS

This Fund is designed for investors with above-average risk tolerance. Please
remember that with any mutual fund investment you may lose money. Principal
risks associated with an investment in the Fund include:

Active Management Risk. The Fund is actively managed and its performance
therefore will reflect in part the ability of the portfolio managers to make
investment decisions that are suited to achieving the Fund's investment
objective. Due to its active management, the Fund could underperform other
mutual funds with similar investment objectives.

Issuer Risk. An issuer may perform poorly, and therefore, the value of its
stocks and bonds may decline. Poor performance may be caused by poor management
decisions, competitive pressures, breakthroughs in technology, reliance on
suppliers, labor problems or shortages, corporate restructurings, fraudulent
disclosures, or other factors.

Market Risk. The market value of securities may fall or fail to rise. Market
risk may affect a single issuer, sector of the economy, industry, or the market
as a whole. The market value of securities may fluctuate, sometimes rapidly and
unpredictably. This risk is generally greater for small and mid-sized companies,
which tend to be more vulnerable to adverse developments. In addition, focus on
a particular style, for example, investment in growth or value securities, may
cause the Fund to underperform other mutual funds if that style falls out of
favor with the market.

                                    -- 6 --


Effective Oct. 17, 2005, the Fund's portfolio managers section is
replaced with the following:

Portfolio Manager(s). The portfolio managers responsible for the
Portfolio's day-to-day management are:

Robert Ewing, CFA, Portfolio Manager

o  Managed the Fund since 2005.

o  Joined RiverSource Investments (previously American Express Financial
   Corporation (AEFC)) in 2002.

o  Prior to that, Analyst and Portfolio Manager at Fidelity Investments from
   1990 to 2002.

o  Began investment career in 1988.

o  BS, Boston College Carroll School of Management.

Nick Thakore, Portfolio Manager

o  Managed the Fund since 2005.

o  Joined RiverSource Investments (previously AEFC) in 2002.

o  Prior to that, Analyst and Portfolio Manager at Fidelity Investments from
   1993 to 2002.

o  Began investment career in 1993.

o  MBA, Wharton School at University of Pennsylvania.

Mr. Thakore provides direct day-to-day management for approximately one-third of
the portfolio optimizing for growth. Mr. Ewing provides direct day-to-day
management for approximately one-third of the portfolio optimizing for value.
Messrs. Ewing and Thakore coordinate day-to-day management of the remainder of
the portfolio, allocating approximately one-third of the portfolio among a team
of research analysts who select investments in their allocations based on the
sectors that they cover. These allocations are generally consistent with the
sector weightings of the S&P 500 Index, an unmanaged index of common stocks, but
allocations may vary.

                                    -- 7 --