Before the Civil War, he was a planter, newspaper publisher, lawyer and South Carolina legislator in 1860 who supported the state calling a secession convention.

He served in the Eastern Theater of the American Civil War, including service as a brigade commander in the Army of Northern Virginia.

[1][2][3] As a member of the South Carolina legislature in 1860, Wallace supported the state calling a convention for the purpose of deciding the issue of secession.

[2][3][4] Wallace married Sarah Smith Dunlap, the great granddaughter of United States Senator John Hunter (South Carolina politician).

[1][2][3][4][5] In the Spring of 1864, the brigade, then commanded by Brigadier General Stephen Elliott, Jr. was ordered to the defense of Petersburg, Virginia.

[1][2] The 18th South Carolina Infantry was holding part of the line under which the Union Army explosive charges were detonated which led to the Battle of the Crater on July 30, 1864.