The first railroad chartered in the United States was the Baltimore and Ohio. Charles Carroll, the last surviving signer of the Declaration of Independence, turned the first spadeful of earth on July 4, 1828. On May 10, 1869, the last golden spike was driven into the newly completed transcontinental railroad built by the Central Pacific and the Union Pacific.
During this period, on May 24, 1844, Alfred Vail was stationed at the Mount Clare railroad depot in Baltimore, Maryland. He decoded the famous telegraph message “What hath God Wrought?” It was sent by Samuel Morse from the Supreme Court chamber of the United States Capitol in Washington, D.C.