Branch Tanner Archer, legislator and secretary of war of the Republic of Texas, son of Maj. Peter Field and Francis (Tanner) Archer, was born in Fauquier County, Virginia, on December 13, 1790. Peter Archer was a Revolutionary War officer. Branch Archer attended William and Mary College at Williamsburg in 1804, and in 1808 he received his M.D. degree from the medical school at the University of Pennsylvania. After returning to Virginia he practiced medicine, served one or two terms in the Virginia legislature (1819–20), and was a presidential elector in 1820. On May 13, 1828, Archer killed his cousin, Dr. James Ottway Crump, in a duel fought with pistols near Scottsville, Powhatan County, Virginia.
Archer arrived in Texas in 1831 and quickly joined a group in Brazoria agitating for independence from Mexico. He represented Brazoria at the Convention of 1833 and participated in the battle of Gonzales in October 1835. In November 1835 he traveled to San Felipe as representative of Brazoria and there was elected chairman of the Consultation. He urged the members to disregard previous factional divisions and concentrate on what was the best course for Texas. Although he favored independence, he voted with the majority, who favored a return to the Constitution of 1824.
The Consultation then selected Archer to join Stephen F. Austin and William H. Wharton as commissioners to the United States to lobby for financial assistance, collect supplies, and recruit men for the Texas cause. The three arrived in New Orleans in January 1836 and negotiated a series of loans that totaled $250,000. Then they proceeded up the Mississippi River, making numerous speeches before turning east for Washington, D.C. During their trip Texas declared its independence, on March 2, 1836. The three commissioners were unable to persuade Congress to support their cause and returned home.
After arriving in Texas Archer worked for the election of Austin as president of the young republic. He also served in the First Congress of Texas and as speaker of the House during its second session. In Congress he and James Collinsworth sponsored a law establishing the Texas Railroad, Navigation, and Banking Company. Subsequently, Archer served as President Mirabeau B. Lamar's secretary of war until 1842.
Archer married Eloisa Clarke on January 20, 1813. They had six children. He was a Mason and helped organize a Masonic lodge in Brazoria. He was grand master of the Grand Lodge of the Republic of Texas in 1838–39. Archer continued to be an active political force until his death. He died on September 22, 1856, at Brazoria and was buried at Eagle Island Plantation on Oyster Creek in Brazoria County. Archer County was named in his honor.