He attended Brown University for two years, at the same time working as a printer to support himself and pay for tuition, but due to his financial distress did not graduate.
In 1836, his brother James Brooks (1810–1873) was one of the founders of the New York Daily Express and Erastus wrote articles and editorials for the paper.
He returned on the packet ship Sheffield which was wrecked off Sandy Hook and lost his literary treasures picked up in Europe.
He was a delegate to the American Party national convention of 1856 in Philadelphia which nominated the Millard Fillmore/Andrew J. Donelson ticket for the 1856 United States presidential election.
Brooks was a delegate to the Constitutional Union national convention of 1860 in Baltimore which nominated the John Bell/Edward Everett ticket for the 1860 United States presidential election.