Born near Pearisburg in Giles County, Virginia in 1795 to Elisha McComas and his wife Ann French McComas, McComas was descended from long-established Virginia families who had helped fight in the American Revolutionary War. He had several brothers and sisters. McComas attended local private schools, then Emory and Henry College, in Emory, Virginia. He married twice. His first wife, Mildred Ward McComas bore at least six sons and two daughters who survived to adulthood: Elisha Wesley McComas, William Wirt McComas, Valeria McComas McComas, Hamilton Calhoun McComas, Rufus French McComas, Benjamin Jefferson McComas and Irene Octavia McComas McKendree. After his first wife's death, he married Sarah V. Wentz Derton, who survived him.
Career
After graduating from college, McComas became Methodist minister, as well as read law and was admitted to the Virginia bar. He moved his young family westward in Virginia along the Midland Trail, establishing his own farm and legal practice in Cabell County near the confluence of the Mud and Guyandotte Rivers.
Political career
McComas served one term as member of the Virginia state senate in 1830–1833. Elected as a Jacksonian to the Twenty-third Congress, McComas won re-election, but as an Anti-Jacksonian, to the Twenty-fourth Congress. He then resumed his farming and legal career, and continued his ministry. Although his former district had been eliminated after the post-1840 census redistricting, McComas again ran for Congress in 1848. He lost, and so did not attend the Thirty-first Congress. His eldest son, Elisha W. McComas, who had served in the U.S. Army during the Mexican-American War, won election as Lieutenant Governor of Virginia in the following decade, but resigned because of how Governor John S. Wise handled the aftermath of John Brown's raid on Harper's Ferry. Elisha McComas then moved to Chicago, Illinois to continue his legal practice, then moved again to Kansas. Meanwhile, as tensions grew concerning slavery, especially after the 1860 U. S. Presidential Election, Cabell County voters elected William McComas as one of their delegates to the Virginia Secession Convention of 1861. Although McComas consistently voted against the secession ordinance, it passed and was approved in a statewide referendum. Some northwestern Virginia delegates then held the Wheeling Convention to prevent secession and eventually established the Restored Government of Virginia and the new state. However, McComas neither attended, nor participated in West Virginia's creation. His family divided. His second son, Dr. William Wirt McComas, who had enlisted in the Confederate artillery, died on April 19, 1862. On September 4, 1862, his third son, Hamilton Calhoun McComas enlisted in the Union Army in Illinois, and served for several months before resigning. His youngest son, Benjamin McComas, enlisted in the 30th Virginia Sharpshooters, a Confederate unit, but survived the war. William McComas continued to serve as judge of the United States district court during the Civil War, residing in the portion which remained loyal to the Union.
Death and legacy
McComas died on his farm near Barboursville, Virginia on June 3, 1865. He was survived by his second wife and several children and grandchildren and interred in the family cemetery.