It's been 50 years since President John F. Kennedy was shot and killed while riding in a motorcade through Dallas, Texas. More words have been written about this event (and its aftermath, and what led up to it) than just about anything else, so we thought we'd take a look back through photographs and video.

We also have a selection of letters of condolences received by the White House, written by political and military figures, celebrities and civil-rights leaders.

All material below provided by the JFK Library in Boston.

Dallas, November 22, 1963:

Returning to Washington, D.C.:

Various letters of condolences: