In 1844 the Whigs carried Ohio, and Corwin was sent to the United States Senate where he remained a powerful figure until his resignation in 1850 to become President Filmore’s Secretary of the Treasury. In 1853 Corwin retired from politics, returned to Lebanon, and resumed his law practice. Five years later, when the Republicans needed a popular orator, he was elected to Congress in the 7th District and re-elected in 1860. After campaigning strenuously for Abraham Lincoln, President Lincoln appointed him to the post of Minister to Mexico, he being a logical choice since he campaigned strenuously as a friend of the Mexicans against the Mexican War in 1847.
Thomas Corwin first appears in the records of Lebanon Lodge No. 26 in the Annual Return of 1822. He is reported to have served as the Worshipful Master of Lebanon Lodge, however, in 1820, 1821, 1824, 1825, and 1843. He served the Grand Lodge of Ohio as Grand Orator in 1821 and 1826, Deputy Grand Master in 1823 and 1827 and as Grand Master in the year 1828.
M. W. Brother Corwin died in Washington, D. C. on December 18, 1865. He once facetiously proposed that his tombstone read “Dearly Beloved by his family; Universally despised by Democrats; useful in life only to naives and pretended friends”. Except for the reference to Sarah Ross Corwin, his wife, and their five children, Corwin obviously was unfair to himself. He was buried in the western half of the Old Section, Lot 98 in Lebanon Cemetery, Lebanon, Ohio with Masonic honors.
One incident of unusual interest concerning Thomas Corwin occurred when he was serving as Secretary of the U. S. Treasury in 1852: he was suspended from the Lodge for non-payment of dues. However, the Lodge members overlooked the fact that W. B. Corwin had advanced 550.00 to the Lodge to assist with financing their rental of the Bradley House in 1842. Later in the year $25.00 was repaid. He was suspended for being $5.50 behind in dues on May 1, 1852. M. W. Bother Corwin had expected that the $25.00 remaining unpaid was being applied to his dues account. A committee consisting of W. B.’s Horace M. Stokes (later Grand Master) and Allen Wright reported on December 27, 1858 that they figured the Lodge owed M. W. Brother Corwin $11.25 above his dues account plus $19.53 interest on the money due him. They submitted their report, without recommendation, and the original report remains in the archives of Lebanon Lodge.