Seventy-six youngsters from the Washington area, ages 9-15, will be competing Thursday, through Sunday in the 1th annual United States youth Games on the campus of Southern Connecticut State College here.

Also represented will be Baltimore, Birmingham, Boston, Detroit, East Orange, Newark, New Haven, New York, Paterson (N.J.), Richmond, Springfield and Worcester (Massachusetts).

Competition will be held in track and field, bowling, basketball, tennis and swimming, with events for both boys and girls.

Washington finished first overall in 1969, 1971 and 1972 and captured the track and field title each year from 1969 through 1974. First, second- and third-place trophies will be awarded in each event this year, but there will be no overall trophy.

The games were conceived in 1966 by New York mayor John Lindsay. They originally included just track and field, bowling and boys' basketball, and the competition was among inner-city youths from New York, Washington and Boston.

In 1967, the games were expanded and, at present 1,000 youths represent 13 cities.

Among the former Olympians to have represented Washington in these games in past years are Adrian Dantley, Kenny Carr, Sheila Ingram and Robin Campbell, who is an assistant coach for the Washington track and field team this year.