[1] The main section of Massachusetts Avenue begins at 19th Street Southeast, just to the west of the former District of Columbia General Hospital site and one block north of Congressional Cemetery.

In the tradition of the acronym SoHo in Manhattan, realtors sometimes refer to this area as NoMa, standing for north of Massachusetts Avenue.

It intersects with Interstate 395, which runs underground at that point, at H Street NW, and passes over Mount Vernon Square in front of the Walter E. Washington Convention Center.

After crossing Rock Creek over Charles C. Glover Memorial Bridge, it curves around the United States Naval Observatory and Number One Observatory Circle, the official residence of the vice President of the United States, which forms the southwest boundary of the Massachusetts Heights neighborhood.

Washington National Cathedral, located at the intersection of Massachusetts and Wisconsin Avenues, is usually considered the end of Embassy Row.

[3] In the 1870s, residential development accelerated on Massachusetts Avenue, mostly around the circles located west of 9th Street NW.

These brick and brownstone structures reflected the Queen Anne and Richardsonian Romanesque styles in vogue at the time.

Luxurious Georgian Revival and Beaux-Arts mansions on Massachusetts Avenuewere late inhabited by wealthy and influential Washingtonians.

After World War II, Massachusetts Avenue was seen as less fashionable than newer areas such as upper 16th Street.