Alexander Manford Headley, Confederate surgeon, merchant, and political figure, son of William and Isabel Hedley, was born at Rothbury, England, in April 1836 and baptized in the old Anglican church there. He changed the spelling of his last name. After prep school in 1853 he served in the British navy, then traveled to Louisiana. In 1856 he entered the Eclectic Medical College of Cincinnati, where he graduated in 1859. He moved to Arkansas shortly afterward, bought property there, and joined the Arkansas State Forces. After Arkansas seceded, Headley was mustered into the Confederate Army at age twenty-five and served as assistant surgeon, then senior surgeon. His hair and beard turned white before the war ended; later in Texas and Mexico he was known as el doctor canoso, the "grey-haired doctor." After the South surrendered, Brig. Gen. Joseph O. Shelby (see SHELBY EXPEDITION) organized a group of volunteers of "undefeated rebels" to go to Mexico, and Headley joined them. They rode through Texas, crossed into Mexico at Eagle Pass, and reached Mexico City in August 1865.
After a brief stay in Mexico City and Córdoba, Vera Cruz, Headley moved north to Camargo, opposite Rio Grande City, Texas. There he established his medical practice and a large mercantile business called Casa de Comercio in early 1866. He was later appointed military commandant of Camargo by Lerdo de Tejada, who succeeded Benito Juárez as president of Mexico. During his service, in November 1875, Texas Ranger captain Leander McNelly crossed into Mexico, killed a number of Mexican citizens, and then retreated to the south bank of the Rio Grande when threatened by Mexican militia. Headley sought a truce under a white flag to investigate.
He married Pilar Treviño, age twenty-eight, his fourth and last wife, in Camargo in 1884, and they had a daughter. He regained United States citizenship in 1880 but continued to practice medicine on both sides of the river. During the epidemic of 1882–83 he treated many cases of yellow fever in Camargo. In Hidalgo County he joined the Republican party and was county commissioner of Precinct 3 in 1890. Contending the Republicans had won an election, Headley led an armed attack on the courthouse at Edinburg (now Hidalgo), evicted the Democrats, who fled to Reynosa, Mexico, and tried to establish his own government. Governor John Ireland dispatched sixty rangers to arrest Headley, but they encountered Headley's forces on guard and surrendered the warrant. In a separate incident, also part of the current political turmoil, the wife of H. T. McCabe, friend and political ally of Headley, shot and killed Hidalgo county judge Max Stein in Reynosa. She was arrested and sent to Matamoros, where Headley rescued her from the police station and escaped to the United States. About a mile from his ranch, Headley was served black coffee laced with arsenic by one of his men. He immediately rode to the ranch, swallowed a bottle of castor oil, and survived. He sold his ranch, moved to Rio Grande City, and continued to practice medicine and lead the Republicans there until his death in February 1912.