 He was again a member of the State Assembly (Delaware Co.) in 1818, 1819, 1820 and 1820–21; and was a delegate to the New York State Constitutional Convention of 1821.He was Lieutenant Governor of New York from 1823 to 1824, but was defeated when running for re-election on the ticket with Samuel Young in 1824.However, in March–April 1824, Erastus Root was honored with two votes at the Democratic-Republican Party Caucus to be the party's candidate for U.S. Vice President at the election later that year.