Since ancient times conquerors have sent mathematicians out to survey what has been taken. Andrew Ellicott (1754-1820), surveyor and mathematician, had a profound impact on the shape of this country (and opined about what had been taken), establishing boundaries of states and cities as well as its international boundaries both north and south. In 1785 he set the boundary of western Pennsylvania and in 1791 surveyed the territory now known as the District of Columbia which was my first motivation in studying Ellicott. In 1796, he surveyed the international border between the U.S. and Spanish territories in Florida under the San Lorenzo Treaty. In 1817, he was appointed astronomer for the United States establishing the boundary between the US and Canada concluding the War of 1812. As a teacher his most famous student was Meriwether Lewis (a second motivation) who needed field instruction before Lewis and Clark´s great expedition to the west. In 1813, he was appointed by President Monroe as a professor of mathematics at the Military Academy at West Point where he was among the first in the country who taught a class in calculus (a third motivation). I will speak somewhat briefly about each of these events.