The company served over 3.2 million clients primarily in the U.S. Dean Witter provided debt and equity underwriting and brokerage as mutual funds and other saving and investment products for individual investors.

Dean Witter offered a broad range of securities and savings products that were supported by the firm's underwriting and research activities as well as order execution.

Closely related to its securities business, Dean Witter provided investment consulting services to individual investors.

Like many of its peers, Dean Witter provides a range of advisory services to corporate clients including mergers and acquisitions, divestitures, leveraged buyouts, restructurings and recapitalizations.

[2][10] With its original offices at 45 Montgomery Street in San Francisco, California, Dean Witter would be among the largest brokerages on the West Coast.

Before founding his own firms, Dean Witter had worked as a salesman for Louis Sloss & Company from his graduation from the University of California, Berkeley in 1909 until 1914.

Although a relatively young company, Dean Witter survived Wall Street Crash of 1929 and the Great Depression, posting profits every year during the 1930s and into the 1940s.

[citation needed] The company grew rapidly during the 1950s and 1960s, establishing itself as a major U.S. brokerage house and developing a reputation for innovation in the securities industry.

In 1938, Dean Witter established its national research department, and in 1945, became the first retail securities firm to offer formal training for account executives.

[20] At the time of its merger with Dean Witter in 1978, Reynolds Securities had over 3,100 employees in 72 offices producing gross revenues of nearly $120 million.

At the time of the Sears acquisition, Dean Witter Reynolds had a retail broker force of over 4,500 account executives in over 300 locations with over 11,500 employees in total.

It carried no annual fee, which was uncommon at the time, and offered a typically higher credit limit than similar cards.

Cardholders could earn a "cashback bonus", in which a percentage of the amount spent would be refunded to the account (originally 2%, now as high as 5%), depending on how much the card was used.

The early 1990s were also a period of rapid growth for Dean Witter Reynolds as its strategy of focusing on the distribution of proprietary mutual funds through its extensive retail brokerage network began to bear fruit.

[32] Dean Witter's corporate headquarters were located in New York City's 2 World Trade Center (i.e. South Tower), where the firm had occupied over 864,000 square feet (80,300 m2) since 1985.

Dean Witter was one of many tenants whose offices were evacuated as a result of the 1993 World Trade Center bombing, which took place during the firm's spinoff from Sears.

[7][8][34][35] Although Morgan Stanley was the more prominent partner, Dean Witter's focus on retail investors, mutual funds and credit cards which were seen by the stock market as generating more stable cash flows than Morgan Stanley's investment banking business had by the time of the merger made it the more valuable partner in terms of market capitalization.

Dean Witter's CEO, Philip Purcell, the main architect of the merger, became chairman and chief executive officer of the merged group.

[37] In order to avoid tension during the integration of the two firms, Purcell and Morgan Stanley's CEO John Mack decided not to choose between the two brand names.

[33] In 2009, the Dean Witter retail operations were transferred to Morgan Stanley Smith Barney, a joint venture with Citigroup.