Grant, born in Davie County, graduated from the University of North Carolina and was licensed to practice law in 1900. He practiced in Mocksville until his death in 1962 and served as county attorney for 29 terms. He was elected the first counselor of the North Carolina State Bar and served for six years. He represented Davie County in the North Carolina House of Representatives for six years between 1903 and 1927. He served three years in the North Carolina Senate. The January 14, 1931 Davie Record reported, "Senator A. T. Grant, Davie County Republican, held a caucus with himself and after some disagreement named himself minority floor leader. Grant, with Roy A. Hartman, Avery County, comprises the Republican delegation in the Senate. "At first it was hard to reach an agreement," Grant remarked humorously. During his last years he served as judge of the Davie County Civil Court.