Waltham ( WAWL-tham) is a city in Middlesex County, Massachusetts, United States, and was an early center for the labor movement as well as a major contributor to the American Industrial Revolution. The original home of the Boston Manufacturing Company, the city was a prototype for 19th century industrial city planning, spawning what became known as the Waltham-Lowell system of labor and production. The city is now a center for research and higher education as home to Brandeis University and Bentley University. The population was 65,218 at the census in 2020. Waltham is part of the Greater Boston area and lies 9 miles (14 km) west of Downtown Boston. Waltham has been called "watch city" because of its association with the watch industry. Waltham Watch Company opened its factory in Waltham in 1854 and was the first company to make watches on an assembly line. It won the gold medal in 1876 at the Philadelphia Centennial Exposition. The company produced over 35 million watches, clocks, and instruments before it closed in 1957. Waltham borders Watertown and Belmont to the east, Lexington to the north, Lincoln and Weston to the west, and Newton to the south.