The school was named after Montgomery Blair, a lawyer who represented Dred Scott in his Supreme Court case, and later served as Postmaster General under President Abraham Lincoln. After opening in 1925 as Takoma Park-Silver Spring High School, the Blair name was adopted in 1935 when the school moved to a location overlooking Sligo Creek at 313 Wayne Avenue. In 1998, the campus moved again two miles (3 km) north to the Kay Tract, a long-vacant site adjacent to the Capital Beltway, and the old building was repurposed to house Silver Spring International Middle School and Sligo Creek Elementary School.