Edward Irving Koch was a United States Representative from 1969 to 1977 and the Mayor of New York City from 1978 to 1989.
Koch was elected Democratic Party district leader of Greenwich Village, holding that office from 1963 to 1965, was a delegate to the State convention in 1964, and was elected to the New York City Council in 1966. In 1965 he made headlines for endorsing Republican John Lindsay for mayor, while still serving as a Democratic district leader.
Koch was the Democratic-Liberal U.S. Representative from New York’s 17th District from 1969 until December 31, 1977, when he resigned to become Mayor of New York City. Koch was the 105th Mayor of New York City, holding that office for three terms, 1978 to 1989.
Source - http://en.wikipedia.org/wiki/Ed_Koch