What's the O-Line?

Historical marker location:

3001 Connecticut Ave NW, Smithsonian National Zoo, District of Columbia

( Marker is on Olmsted Walk, 0.2 miles west of North Road, on the left when traveling west.)

The District was the site of the first U.S. public school for black students: The M Street School (later known as Dunbar High School) was founded in 1870 and was the first public school in the United States for black students. The school became known for its high academic standards and produced many notable alumni, including civil rights leader and educator Mary McLeod Bethune.