Surveyors have special reason to celebrate President’s Day, since Washington, Jefferson, Lincoln and even Teddy Roosevelt all had surveying and map-making in their backgrounds. Jefferson’s surveying experience informed his acts as president, including the establishment of the Public Land Survey System (PLSS) and the Louisiana Purchase that added 827,000 square miles of land to the United States.

By the 1800s, the westward expansion was continuing unabated, despite land being inhabited by indigenous peoples as well as claimed by other countries.