Meanwhile, Carr published several articles on non-legal topics. Using the pseudonym Obediah Squaretoes, Carr contributed a satirical article to William Wirt's The Old Bachelor (1814).
Carr started his private legal practice in Albemarle and adjoining counties in 1796. In 1802 Albemarle voters elected him commonwealth's attorney (prosecutor), and Carr served for a decade, until resigning in March 1811 to become an interim judge when William H. Cabell was elevated to what was later known as the Virginia Supreme Court (and on which Carr would also later serve).