More than 400 persons will join the Greater Washington Board of Trade tomorrow night in paying tribute to former D.C. mayor Walter E. Washington as the board's 1983 Man of the Years.

Although most recipients have been former presidents of the Board of Trade, the coveted award is intended to honor persons who have "given long-standing commitment to the total development of the city," a board official explained.

Washington's record in that regard "was so superb, it was just a unanimous decision" to name him the 1983 Man of the Years, the official added.

Washington, 68, is best remembered for his calm and diplomatic leadership in guiding the District through its most difficult period in modern history. Less than six months after President Lyndon B. Johnson made him the District's first appointed mayor, the city's streets erupted in violence as news of Martin Luther King Jr.'s assassination spread.

Against a backdrop of flames and smoke, Washington calmly walked the city's riot-torn streets calling for restraint and unity.

As the District's first appointed mayor, "Walter acquitted himself very well and he brought us through the riots and provided the leadership to rebuild the city," recalled Thomas J. Owen, chairman of Perpetual American Federal Savings and Loan Association and president of the Board of Trade.

"I would think Walter provided stability in a time when a different kind of mayor could have encouraged an atmosphere that could have proved disastrous for business and the entire community," Owen continued.

Despite Washington's efforts to calm the fears of all segments in the community in the wake of the riots, he was unsuccessful in preventing an exodus of scores of businesses to the suburbs.

Many who stayed, however, agree that Washington's calm diplomacy and his calls for restraint and a partnership to rebuild the city were the primary factors in their decision to remain.

"Some might say that he wasn't assertive enough, but who knows? I think he was the right man for that time," Owen said.

He was the "perfect man" in fact, said Edwin K. Hoffman, chairman of Woodward & Lothrop Inc. and a former Board of Trade president.

As a member of Woodies' board, Washington is a "solid director" who "works extremely hard and keeps everybody's nose to the grinding stone," Hoffman said. "He is very perceptive and has a very broad point of view. My company is very lucky."

Washington also sits on the boards of Geico Corp., National Permanent Savings Bank and District Title Realty Insurance Corp.

He had established strong ties with the District's business community long before he became mayor. As director of the old National Capital Housing Authority, Washington worked to establish a partnership between business and government in an attempt to alleviate some of the city's housing problems.

His appointment as mayor and his subsequent election to another term coincided with the Board of Trade's shift away from the more narrow interests of the business sector to a broader-based involvement in community affairs. Some say Washington played a pivotal role in that evolution.

"When I came into office, I looked to all segments, the former mayor recalled. "I had to call on all segments of the community in order to help me restore the city and house and feed the people."

With business' support on Capitol Hill, Washington said his administration was able to accomplish some of its greatest achievements, such as winning the fight for Home Rule and congressional approval to build the convention center.

Also notable, he said, were his administration's successes in getting commitments from developers to invest in commercial projects that would spur development around the center and transferring highway entitlement funds into Metro construction--assuring the start of a rapid transit system linking city and suburbs.

Many in the business community--despite swinging their crucial financial support to Washington's eventual successor in 1978--concede that Washington set the tone and restored confidence that led to the present economic upturn.

And by developing a "viable infrastructure from public works programs," he said, "from a business standpoint, I would think that that would put the city in good stead when it goes to the bond market."

Born in rural Georgia and reared in Jamestown, N.Y., Washington came to the District during the Depression years and graduated from Howard University. Following a long career in government service, he served as director of NCHA for five years before being appointed mayor. He is now a partner in a local law firm.

"I love the city with a passion," he said recently. "I have given my blood and sweat to the city, both in housing and as mayor."