He later graduated from Cumberland College (1813) and later studied law, being admitted to the bar in 1820.

[2] He also served in the Creek War and was for a time private secretary to General Andrew Jackson.

He was a member of the Tennessee House of Representatives from 1829 to 1831 and again from 1835 to 1837, serving each time as Speaker.

The legislature elected him to continue in the new term, but he declined, refusing to take their instruction in how to vote while a Senator; the legislature then turned to Grundy, still Attorney General, to succeed him, which (controversially) Grundy agreed to do.

Following this, Foster returned to his Nashville law practice until shortly before his death.