Martin Van Buren and Josiah Quincy are the two most prominent politicians who come to mind who were alive for both wars. However Van Buren wasn't born until 1782, and Josiah Quincy wasn't born until 1772 making him extremely young for the duration of the revolutionary war. Quincy is notable for continuing to claim to being a Federalist for his entire life, well after his party had gone defunct, but certainly neither man wielded much if any political influence at the time of either war.