Career
Born in Winsted, Connecticut, Groppo served in the United States Marine Corps during World World War World War II He was a stonemason and was the owner of Leo Groppo & Son Mason Contractors. He served as mayor of Winsted, Connecticut 1965 to 1967. From 1959 to 1985 he served in the Connecticut House of Representatives as a Democrat and was majority leader.
In 1985-1987, Groppo was commissioner of the Connecticut Department of Revenue Services.
He died in Winsted, Connecticut.