In 1789 President George Washington signed into law the creation of the U.S. Lighthouse Establishment under the first Secretary of Treasury, Alexander Hamilton, and in 1807 Congress established the U.S. Coastal Survey. Between 1842 and 1845, Nantucket astronomer William Mitchell observed that nearly 45,000 ships of all designs had passed near Nantucket Shoals. In 1848 Congress appropriated $12,000 for the construction of a lighthouse on this site, including $250 for the 10-acre parcel, and in 1849, supervised by engineer Benjamin Franklin Isherwood, construction began and included a brick keeper's house that became the home of the light's first full-time keeper, Alexander D. Bunker. In 1850 Sankaty Light flashed for the first time, powered by a whale-oil lantern and shining through a second-order Fresnel lens, one of the most powerful lenses in use in its day; the lens remained in use for 100 years and is now on display at the Nantucket Whaling Museum. In 1852 Congress reorganized the Lighthouse Establishment, renamed it the Lighthouse Board, and created the U.S. Lighthouse Service; citing the superior power of Sankaty Light's beam, the Board ordered all U.S. lighthouses to have Fresnel lenses. In 1888 the lantern was raised an additional 10 feet, in 1912 an incandescent oil-vapor lamp was installed to improve projection, in 1933 the lighthouse was electrified, and in 1950 the Fresnel lens was removed and replaced by a modern rotating aero beacon. In 1969 the U.S. Coast Guard removed the deteriorating cast-iron lantern room, which had withstood 120 years of salt spray, hurricanes, and nor'easters, and after complaints about the tower's new look, the current aluminum replacement lantern was installed. During the 1980s and 1990s, vigorous erosion made clear that the lighthouse might have to be moved to safer ground. The 'Sconset Trust was formed in 1984, Sankaty Light was placed on the National Register of Historic Places in 1987, Save Our Sankaty was established in 1992 to heighten community awareness of the lighthouse's plight, Preservation Massachusetts placed it on its Ten Most Endangered Resources list in 1993, and in 1994 the 'Sconset Trust, Save Our Sankaty, the Nantucket Historical Association, and the U.S. Coast Guard undertook a concerted effort to address its fate. From 2000 to 2006, as erosion continued at an average of 3 feet per year from the bluff, the 'Sconset Trust and its members worked with federal, state, and local officials to prepare for relocation and contracted International Chimney, Inc., of Buffalo, N.Y., an established U.S. expert in relocating and preserving lighthouses. In 2007, with funding and permits in place, a new foundation was built 405 feet to the northwest on Sankaty Head Golf Club land, and the 10-day move was completed on October 10th. In 2008, under the ownership of the 'Sconset Trust, the lighthouse was preserved at its new location and the landscape was restored.