Baltimore–Washington telegraph line

Lore & Background

The line was authorized by the US Congress in March 1843, which appropriated funds to Samuel Morse to lay a telegraph line between Washington, D.C., and Baltimore, Maryland, along the right-of-way of the Baltimore and Ohio Railroad. Morse originally decided to lay the wire underground, asking Ezra Cornell to lay the line using a special cable-laying plow that Cornell had developed. Wire began to be laid in Baltimore on October 21, 1843. Cornell's plow was pulled by eight mules, and cut a ditch 2 inches wide and 20 inches deep, laid a pipe with the wires, and reburied the pipe in an integrated operation. However, the project was stopped after about 15 km of wire was laid because the line was failing.

Morse learned that Cooke and Wheatstone were using poles for their lines in England and decided to follow their lead. Installation of the lines and poles from Washington to Baltimore began on April 1, 1844, using chestnut poles 7 m high spaced 90 m apart, for a total of about 700 poles. Two 16-gauge copper wires were installed; they were insulated with cotton thread, shellac, and a mixture of beeswax, resin, linseed oil, and asphalt. A test of the still incomplete line occurred on May 1, 1844, when news of the Whig Party's nomination of Henry Clay for U.S. President was sent from the party's convention in Baltimore to the Capitol Building in Washington.

Morse's line was demonstrated on May 24, 1844, from the Old Supreme Court Chamber in the United States Capitol in Washington to the Mount Clare station of the railroad in Baltimore, and commenced with the transmission of Morse's first message (from Washington) to Alfred Vail (in Baltimore), "What hath God wrought", a phrase from the Bible's Book of Numbers. The phrase was suggested by Annie Ellsworth, whose husband was a supporter of Morse's, and knew Morse was religious. As U.S. Postmaster General, Cave Johnson was in charge of the line. Morse was made superintendent of the line, and Alfred Vail and Henry Rogers the operators.

Reader's Guide

The Baltimore–Washington telegraph line demonstrated the practical viability of long-distance electrical communication in the United States. Its construction overcame early technical failures—the underground cable laid with Ezra Cornell's plow proved unreliable after about 15 km, forcing a shift to overhead poles inspired by English practice. The line's successful operation, culminating in the transmission of "What hath God wrought" on May 24, 1844, marked the beginning of the telegraph era in America. The following year, U.S. Postmaster General Cave Johnson reported that "the importance of [the line] to the public does not consist of any probable income that can ever be derived from it," which led to the invention being returned for private development. This assessment proved shortsighted, as the line's legacy lies in proving that telegraphy could work over distance, paving the way for the rapid expansion of telegraph networks across the continent. The line also established key operational roles—Morse as superintendent, Alfred Vail and Henry Rogers as operators—and introduced the now-famous first message, a biblical quotation chosen by Annie Ellsworth.

Did You Know?

• The line originally used underground cable laid by a plow pulled by eight mules, but failed after about 15 km.
• A test of the incomplete line on May 1, 1844, sent news of Henry Clay's presidential nomination from Baltimore to Washington.
• The first message, 'What hath God wrought,' was suggested by Annie Ellsworth, whose husband supported Morse.
• The line used about 700 chestnut poles, each 7 m high and spaced 90 m apart.