Elisha Clapp, soldier and farmer, was born in Tennessee about 1803 and immigrated to Texas in 1822; he settled at Nacogdoches. He enlisted in Capt. Henry Wax Karnes's cavalry company on April 7, 1836, and participated in the battle of San Jacinto. Afterward he was detached to guard Mexican prisoners. He was discharged from the army on May 28, 1836. For his service Clapp received a labor of land in Houston County. On September 10, 1836, he was elected captain of a company of mounted rangers at his home at Mustang Prairie. Sam Houston, as commander in chief of the Texas army, ordered his company to "range from any point on the Brazos to Mr. Hall's Trading House on the Trinity" to intercept parties of raiding Indians. Clapp organized an expedition against the Ionie Indians, who, according to one settler, "have been committing some depredations in the horse stealing way" on the frontier.
On May 31, 1837, President Houston nominated Clapp for a commission as captain and appointment to the command of the ranger company from Nacogdoches County. The Senate confirmed the nomination on June 13. Although Houston noted in his instructions to the auditor that Clapp was illiterate and that his muster roll must be monitored with special care, when Clapp moved to the Houston County community of Alabama he helped to organize and became one of the first eleven trustees of Trinity College, in April 1841. By March 1, 1849, he had moved to Leon County, where he and his wife, Rebecca Elizabeth (Robbins), and six of their eight children were living at the time of his death, which the Texas Presbyterian reported on December 6, 1851. Other sources state that he died in 1856. The value of his real property was estimated as $17,800.