[6] Gregg served for the Union in the Civil War and held many prominent positions, but is perhaps best known for his efforts to locate the University of Arkansas in Fayetteville.

He taught school to support himself until passing the bar exam and establishing a law practice, ultimately rising to become a prominent attorney in town.

[15] During the Civil War, Colonel Lafayette S. Gregg was in charge of Company S, 4th Arkansas Cavalry Regiment from 16 October 1864, until 30 June 1865.

Gregg was soundly defeated, which was typical of Republican candidates during the Solid South period that followed the Reconstruction era.

[15] Following the Arkansas Industrial University's founding in 1871, Gregg was elected to the board of trustees and served on the buildings committee.

Gregg donated land to the American Missionary Association for a school for Black children and advocated for Arkansas's inclusion in the Columbian Exposition.