In the United States, the first optical telegraph was built by Jonathan Grout in 1804 but ceased operation in 1807. This line between Martha's Vineyard with Boston transmitted shipping news. An optical telegraph system linking Philadelphia and the mouth of the Delaware Bay was in place by 1809 and had a similar purpose; a second line to New York City was operational by 1834, when its Philadelphia terminus was moved to the tower of the Merchants Exchange. One of the principal hills in San Francisco, California is also named "Telegraph Hill", after the semaphore telegraph which was established there in 1849 to signal the arrival of ships into San Francisco Bay.