U.S. Capitol Building Pin. Die Struck from jewelers metal, enamel color filled, gold plated and polished to a great shine. This great pin features the U.S. Capitol Building in the forefront of our American Flag! The Capitol building is home to our U.S. Government's Legislative Branch - the U.S. Congress, including the House of Representatives and the Senate. This is also considered "Capitol Hill" in Washington, DC. Each pin comes with a clutch back is individually poly bagged.