A “Peter Jennings Reporting” (8 p.m., ABC) recalls the August 1963 civil rights march on Washington, D.C., culminating in Dr. Martin Luther King Jr.’s most memorable address, best known as his “I Have a Dream” speech.

While the modern civil rights struggle had begun in earnest in the mid-1950s, the march on Washington forced many, in and out of government, to focus on the problem for the first time. As Jennings observes, “It was the first time white America — and the world — heard Dr. King’s message in all its eloquence.”

The special provides a perfect example of how difficult it can be to provide historical information and perspective in the space of a one-hour documentary. Jennings goes about explaining the traumatic events of 1963, including King and his colleagues’ decision to use children to lead the protests in the segregated city of Birmingham, Ala. Newspaper photos and TV news footage of the Birmingham police using high-pressure fire hoses and vicious police dogs to subdue grade school students horrified viewers all over the world, and was said to personally sicken President John F. Kennedy.

The documentary fails to explain some of the political realities facing Kennedy and his Democratic Party, however. While the South has become a Republican bastion in recent decades, JFK owed his very election to a solid block of Democratic-voting Southern states. This electoral base would begin to disappear after 1964, when the Democratic Party began to champion civil rights. The word “union” is uttered only once, even though many of the marchers seen in vintage footage are carrying placards stating their union affiliation.

Jennings also completely ignores the pressure that Dr. King and his movement felt from more militant black power advocates. Malcolm X is mentioned only in passing, when Jennings reels off a list of those who fell to assassins during the 1960s.

But even an incomplete history is better than no history at all. Jennings and ABC News deserve praise for a proper commemoration of a day and a speech that changed America.

• Chris Rock plays host to the “Video Music Awards” (6 p.m., MTV), live from Radio City Music Hall in Manhattan.
• On tonight’s repeat of “ER” (8:59 p.m., NBC), Abby contends with an overmedicated patient. In other “ER” news, NBC announced that Linda Cardellini will be joining the show. Viewers may know her from her role as Velma in the 2002 “Scooby Doo” adaptation

Tonight’s other highlights

• On back-to-back episodes of “CSI” (CBS): A hit-and-run is more than it seems (6 p.m.), death stalks the stand-up circuit (7 p.m.).
• Four couples and a band of frisky singles set sail for “Temptation Island 3” (7 p.m., Fox).