The Texas School Book Depository was a private firm that distributed textbooks to schools in North Texas and Oklahoma from a non-descript 7-story, red-brick warehouse that had stood on the corner of Elm and Houston streets since 1901.†
Accused assassin Lee Harvey Oswald began working at the depository as an order filler on Oct. 15, just a few weeks before the assassination of President John F. Kennedy.††
Oswald is believed to have fired three shots at Kennedy's presidential motorcade from a makeshift sniper's nest on the southeast corner of the sixth floor of the building.
"He worked principally on the first and sixth floors of the building, gathering books listed on orders and delivering them to the shipping room on the first floor. He had ready access to the sixth floor, from the southeast corner window of which the shots were fired," the Warren Commission report states.
After the assassination, a rifle and three shell casings were found on the floor near an open window on the sixth floor.††† Many witnesses to the assassination in Dealey Plaza recalled seeing a man with a rifle in the window.
Dallas County acquired the building in 1977, seven years after the depository moved out of the building. After a major renovation, the first five floors were put into use as a county administration building beginning in 1981 -- though the sixth and seventh floors remained unused.†
On President's Day 1989, The Sixth Floor Museum opened as a historical exhibition of the darkest day in Dallas' history and includes "two key evidentiary areas" that have been restored to their 1963 appearance -- including the sniper's nest.†
In 2002, the museum opened a gallery on the seventh floor and now occupies the top two floors of the 112-year-old warehouse.†
† Source: JFK.org - History of the Texas School Book Depository
†† Source: Archives.gov - Oswald at Window
†††Source: Archives.gov - Discovery of Cartridge Cases and Rifle