Baltimore–Washington telegraph line

Morse learned that Cooke and Wheatstone were using poles for their lines in England and decided to follow their lead.

[6] Two 16-gauge copper wires were installed; they were insulated with cotton thread, shellac, and a mixture of "beeswax, resin, linseed oil, and asphalt.

[7] 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.

Morse was made superintendent of the line, and Alfred Vail and Henry Rogers the operators.

[5] The next year, 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.

The first telegram. Professor Samuel Morse sending the dispatch as dictated by Miss Annie Ellsworth
Text of the first telegraph message sent by Samuel F. B. Morse . Presented to Miss Annie G. Ellsworth, daughter of Henry Leavitt Ellsworth. Annie's ink tracing over Morse's pencilled letters. Gift to Library of Congress by Mrs. George Inness, daughter of Annie Ellsworth
Maryland state historical marker of the first telegraph message, located between US Highway 1 and railroad tracks in Beltsville, Maryland .