By the end of the American Civil War, as roads and transportation improved, Westford began to serve as a residential suburb for the factories of Lowell. Throughout the 20th century, Westford progressively grew, continuing to provide residential housing for the industries of Lowell and, later, Boston.
In the 1960s, the town was home to one of the research sites supporting Project West Ford. By the 1970s, with the advent of the 128 Technology Belt, Westford began to act as a suburb for high-tech firms in Burlington, Woburn and other areas, later becoming a center of technology itself. By the 1990s, Westford was home to offices for Red Hat, Samsung, Seagate, Iris Associates, Visual Solutions and many other technology firms. It is also the North American headquarters for Puma. The leading manufacturer of EEG electrodes, HydroDot Inc., located to Westford in 2007. In addition to rapidly expanding high-tech industries, Westford is characterized by suburban retail and upper-middle class residential areas.