William Mordecai Cooke Sr.

William Mordecai Cooke Sr. (December 11, 1823 – April 14, 1863) was an American judge and politician. Born in Virginia, he moved to Missouri and practiced law before getting involved in politics and supporting secession and slavery. He was a member of the Provisional Confederate Congress and First Confederate Congress, representing Missouri from 1861 to his death in 1863.

Early life William Mordecai Cooke was born on December 11, 1823, in Portsmouth, Virginia, the sixth of eight children to Margaret (née Kearnes) and Mordecai Cooke V. His father was a member of the Virginia legislature. He was descended from English settlers of Gloucester County, Virginia. He was educated by private tutors and studied mathematics, natural philosophy, moral philosophy, and chemistry. He was also a planter. In 1854, he returned to St. Louis. In 1856, he ran for judge of the land court in St. Louis.

Cooke was proslavery and was in favor of secession, favoring the slaveowning values of his Virginia heritage. He was then a member of the First Confederate Congress, representing Missouri, and built a strong relationship with Jefferson Davis. He proposed a bill in January 1862 "to encourage enlistments... in the state of Missouri". He was initially buried in Petersburg. He was buried in Calvary Cemetery in St. Louis.