Tom Brokaw narrates this documentary on Martin Luther King Jr. For some of us, it's hard to believe that Dr. King was assassinated 40 years ago this month at the age of 39. Dr. King knew he would die young - before he reached his 40th birthday. He knew in his heart he would be assassinated.

The documentary includes interviews with and comments from Bill Clinton, Condoleezza Rice, Harry Belafonte, Andrew Young, Bono, Martin Luther King III, and more. King had an enormous impact with his efforts of non-violent protests and received the Nobel Pease Prize in 1964, the youngest recipient to receive the accolade. He donated the entire $54,123 in prize money to the civil rights movement.

In August, 1963, Dr. King delivered his defining speech in Washington, D.C. The "I Have a Dream" speech is considered one of the most important speeches of all time. However King suffered from bouts of depression and at times his dream turned into a nightmare. The demands on this man were enormous, yet he never failed to assist the cause against injustice whenever he was called upon. When he was in jail in Birmingham in 1963, he wrote his famous "Letters from a Birmingham Jail" about the struggle against segregation.

After the success in integration and voting rights, King turned his attention to poverty. He said the three causes that he dedicated his life to were racism, economics, and militarism. The latter caused much controversy as many people thought he should not get involved in the protests against the Vietnam War.

Dr. King was a man of conscious. He left a legacy that is more than just a footnote in American history. His son, Martin Luther King III, is now older than his father was when he was assassinated and carries on the family tradition with the "Realizing the Dream" foundation against poverty.

This is an amazing documentary. The music, the comments, the background and footage combine to make this a comprehensive story of the life and work of Dr. Martin Luther King, Jr. It's a piece of the history puzzle, and an impressive piece at that. It's a look at the man and his dream.

King premiers Sunday, April 6 at 8 PM ET/PT on the History Channel.