Blair Jr., Francis Preston, 1821-1875

Blair was born in Lexington, Kentucky. He was the third and youngest son of newspaper editor and politician Francis Preston Blair, and Eliza Violet (Gist) Blair. He was the brother of Montgomery Blair, a Mayor of St. Louis and Postmaster General under Lincoln, and the cousin of B. Gratz Brown, a U.S. Senator and Governor of Missouri. Blair attended schools in Washington, D.C., was matriculated in Yale and the University of North Carolina, but graduated from Princeton University in 1841, and then studied law at Transylvania University. After his admission to the Kentucky bar in Lexington, he went on to practice in St. Louis in 1842 with his elder brother; in 1842–1845, he worked in the law office of Thomas Hart Benton.

In fall 1845, Blair traveled to the West for buffalo hunt and stayed for a winter in eastern Colorado with his cousin George Bent in Bent's Fort, a settlement on the Santa Fe Trail. After the Mexican–American War started he joined the expedition of General Stephen W. Kearny in Santa Fe, who then appointed Blair as an attorney general for the New Mexico Territory after it was secured. In collaboration with Alexander William Doniphan, Willard Preble Hall, and David Waldo, Blair developed an American Code of Law for the region and became a judge of the newly established circuit court.

...