Alexander Stewart of the Southern Confederation.
Alexander Stewart was an early nineteenth century abolitionist in the Southern Confederation. Along with Theodore Bailey, he founded the Anti-Slavery Society in 1821. Although the Society had little support at first, the steady succession of slave uprisings in the 1820s increased its membership to the point where Stewart and Bailey were able to join with other abolitionist organizations to create the Southern Union Party in 1825. By the end of the decade, the Conservative Party had adopted the Southern Unionist position on slavery.
Although Sobel does not specifically say so, it is possible that Stewart accompanied Carter Martin to the United States of Mexico in 1842 to try to persuade that nation to abolish slavery as well.
Stewart does not have an entry in Sobel's index.