Marblehead Lighthouse, the oldest lighthouse in continuous operation on the Great Lakes, has guided sailors safely along the Marblehead Peninsula's rocky shores since 1822. Throughout its history, fifteen lighthouse keepers, two of whom were women, have tended the beacon. Benajah Wolcott, a Revolutionary War veteran and one of the first settlers on the peninsula, was the first keeper. Upon Wolcott's death in 1832, his wife, Rachel, took over these duties. The U.S. Congress set aside $5,000 in 1819 to construct the 50-foot tower using native limestone. Originally lit by whale-oil candles, the Marblehead Lighthouse now guides ships to shore using LED light projecting a green signal that flashes every six seconds and is visible for eleven nautical miles.