Samuel Dickinson Hubbard was born in 1799 in Middletown, Connecticut. He graduated from Yale College in 1819, studied the law, and was admitted to the state bar in 1820.

Hubbard established a law practice in Middletown, but an inheritance allowed him to switch his focus to business. He also became interested in politics and was elected as a Whig to the United States House of Representatives in 1844, serving until 1849.

In 1852, President Millard Fillmore tapped Hubbard to serve as postmaster general for the remaining six months of his administration. After leaving office in 1853, Hubbard devoted the rest of his life to serving educational and charitable organizations. Samuel Dickinson Hubbard died in 1855.