From 1823 to 1829 he attended the Boston Latin School, but his education was put on hold while he traveled for six months to Saint Petersburg, Russia with his father.

While reporting political affairs he became friends with Henry Clay, Daniel Webster and John C. Calhoun.

During this time he also collaborated with Samuel Griswold Goodrich, writing the Peter Parley books, which embellished the biographies of our founding fathers with "fancy and legend".

[4] Sargent's first play, The Bride of Genoa, premiered at Boston's Tremont Theatre on February 13, 1837, with a lead role written for American actress Josephine Clifton.

[4] In 1846 he wrote and edited The Modern Standard Drama, a seven volume collection of the most popular acting plays of the time.

[2] Sargent was considered a member of the "Knickerbocker group", a group which also included Washington Irving, William Cullen Bryant, James Kirke Paulding, Gulian Verplanck, Fitz-Greene Halleck, Joseph Rodman Drake, Robert Charles Sands, Lydia M. Child, and Nathaniel Parker Willis.

He published Planchette, or the Despair of Science (1869), The Proof Palpable of Immortality (1875), and The Scientific Basis of Spiritualism (1880).