Born in Beaufort, South Carolina, Grayson pursued classical studies, and was graduated from South Carolina College at Columbia in 1809.He studied law.He was admitted to the bar in 1822 and commenced practice in Beaufort, South Carolina.He served as member of the State house of representatives from 1813 to 1815 and 1822-1825.He served in the State senate 1826-1831.

Grayson was elected commissioner in equity for Beaufort District in 1831 and resigned from the senate.

Grayson was elected as a Nullifier to the Twenty-third and Twenty-fourth Congresses (March 4, 1833-March 3, 1837).He served as collector of customs at Charleston from August 9, 1841, to March 19, 1853.He retired to his plantation.He was a frequent contributor to the Southern Quarterly Review.He died in Newberry, South Carolina, on October 4, 1863.He was interred in Magnolia Cemetery, Charleston, South Carolina.