A chapeau-bras is a hat that can be folded and carried under the arm. This hat belonged to Cassius Marcellus Clay. Clay was a Kentucky politician who fought against slavery. He was friends with Abraham Lincoln. The hat is from Russia, where Clay served as an ambassador from the United States. In Russia, Clay saw millions of Russian serfs, peasant workers who had no rights, set free. This experience helped him influence Lincoln to free the slaves in America.