"Fort Ticonderoga, originally Fort Carillon, was built by the French military between 1755 and 1759. One of a series the French built to control Lake Champlain. The site looks over Lake Champlain at a point where it narrows and the shore of Vermont is a mere cannon shot away. It is at this point, too, that the waters from Lake George enter Lake Champlain via the La Chute River. Control of this strategic narrows meant control of the north-south water "highway"......"
This excerpt is from the following website:
http://www.fort-ticonderoga.org/history/18th-century.htm