 He spent 1822 to 1850 engaged in mercantile pursuits in New York City before moving to St. Augustine, Florida in 1865.An early advocate of abolitionism, Gilbert was a strong supporter of the Whig Party and, later on, the Republican Party.He was elected to represent Florida in the United States Senate as a Republican, and served from 1869 to 1875 as part of the Reconstruction effort.