McComas served one term as member of the Virginia state senate (a part-time position) 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 (March 4, 1833 – March 3, 1837). 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 (1822-1890), 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 (1831-1883, and another lawyer) enlisted in the Union Army in Illinois, and served for several months before resigning. His youngest son, Benjamin McComas (1836-1894), 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 (first as the
Restored Government of Virginia and then the new state of
West Virginia beginning in June 1863). ==Death and legacy==