Francis and his brother Tom heard William B. Travis's plea for help from a courier and, with ten or twelve others from the area, joined Col. Albert C. Horton's company on its way to join James W. Fannin, Jr. The two brothers traveled to Victoria and there volunteered with seventeen others to transport a wagonload of lead and powder from Dimitt's Landing to the main army at Beeson's Ford. They were successful in this mission and fortunate to have volunteered for it, as most of the men who stayed at Victoria were killed. In the meantime, the rest of the Cooke family was fleeing in the Runaway Scrape; they eventually returned to their home after the war.
At Beeson's, Tom and Francis joined Capt. Robert J. Calder's company, in which Francis and his brother fought at the battle of San Jacinto. The night before the battle a friend in his company, Benjamin Brigham, asked someone to stand guard duty in his place, since he had been on duty the last two nights. Francis gave Brigham his bed for the night. Brigham was one of the first to be killed the next day in battle, and it is said that Mirabeau B. Lamar wrote his poem on the battle after viewing the body of Brigham and others. Francis Cooke continued to serve for a short time after the battle and served as one of Santa Anna's guards.
After the war he received 320 acres of land for his service from March 17 to June 20, 1836, and later 640 acres of land for his part at San Jacinto. In 1842 he enlisted again in the army for three months in Col. Joseph L. Bennett's regiment to take part in the campaign against Adrián Woll, though he did not join the Mier expedition. He served in the Texas Rangers for six weeks in 1843.
Cooke tried his skills as a merchant in both Houston and Brenham. While in Brenham, he fell ill and was nursed back to health by Mr. and Mrs. Hugh McIntyre, Sr. On December 28, 1845, he married their niece, Emily Stockton. He was involved as a partner in businesses in Brenham, Houston, Chappell Hill, and Hempstead before retiring to his farm near Hempstead. He and Emily had eleven children, one of whom grew up to be "Senator" Annie Cooke, an influential figure in Texas politics in the first half of the twentieth century. Cooke died on November 11, 1903, and was buried in Salem Cemetery, near Howth. He was a member of Holland Masonic Lodge No. 1 of Houston and of the Texas Veterans Association. Emily died on September 4, 1908. In 1936 the state had a Texas Centennial monument placed at their graves, probably under the influence of Annie Cooke.
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