Baltimore's Third System defense, Fort Carroll was named in 1850 to honor Charles Carroll, a signer of the Declaration of Independence. It is located on a man-made island in the Patapsco River adjacent to the Francis Scott Key Bridge. The construction was once supervised by Robert E. Lee. It is hexagonal and includes three modern coastal batteries. They are Battery Towson (1900 - 1918), Battery Heart (1900 - 1917), and Battery Augustin (1900 - 1920). The single story fort was origginally intended to have four tiers. The fort was abandoned after WWI. The Coast Guard used the fort during World War II. A lighthouse was added in 1854 and rebuilt in 1898. The lighthouse and the fort were abandoned after World War II. The fort was originally known as Fort at Soller's Point during its construction. During the Civil War, Fort Carroll had only five gun platforms ready in April 1861, and only two were armed with guns, out of a planned 225 gun emplacements. Privately owned, and with no public access, it is overgrown and deteriorating. The best views are from Fort Armistead.