Between June 11 and June 28, 1776, Thomas Jefferson drafted the Declaration of Independence, which the Continental Congress adopted on July 4, 1776; it was engrossed on parchment, and delegates began signing it on August 2, 1776. Drafted by delegates to the Constitutional Convention during the summer of 1787, the four-page Constitution of the United States, signed on September 17, 1787, established the government of the United States. The Pledge of Allegiance, composed by Francis Bellamy in 1892 and formally adopted by Congress in 1942, is presented as an expression of loyalty to the flag of the United States, with its last language change made on Flag Day 1954 when the words "Under God" were added. On September 13, 1814, Francis Scott Key penned a poem that was set to music and in 1931 became America's national anthem, "The Star-Spangled Banner." Veterans are honored as men and women who have sacrificed and dedicated themselves to protecting and preserving the principles of freedom on which the nation was founded, including those who have served, are serving, and will serve in the United States Armed Services.