FBI called MLK 'most dangerous Negro' in the U.S. after 'I Have a Dream' speech

Wednesday night on "The Rachel Maddow Show," host Rachel Maddow discussed the fact that not everyone in the U.S. government was happy about the March on Washington in 1963. The Federal Bureau of Investigation -- under the leadership of ultra-conservative cross-dresser and closeted gay man J. Edgar Hoover -- considered the civil rights marchers to be instruments of the global communist threat within U.S. borders.

The FBI kept extensive records on Rev. Martin Luther King Jr. in particular, recording his phone conversations and keeping agents on a constant surveillance beat. In the days after his historic "I Have a Dream" speech, Hoover circulated an FBI memo that said, "In light of King's powerful, demagogic speech yesterday, we must mark him now, if we have not done so before, as the most dangerous Negro of the future in this Nation from the standpoint of Communism, the Negro and national security."

Hoover sent that memo around Washington, the the White House and the Pentagon. By October of 1963, Attorney General Robert F. Kennedy authorized unlimited wiretapping and bugging of the civil rights leader.

"Eight wire taps, 16 bugs," Maddow said, "his phones, his hotel rooms, his bedrooms. And they used the sound that they collected, the used the information they collected in those wiretaps to try to destroy Dr. King, both professionally and personally."

"When he was awarded the Nobel Peach Prize," she continued, "J. Edgar Hoover personally convened a press conference in his office in which he personally called Martin Luther King a 'notorious liar.'"

FBI intelligence chief Bill Sullivan reportedly assembled a compilation of recorded sounds of King having sex with women who were not his wife, wrote a threatening letter and sent the package to King at home.

"King," Sullivan wrote, "look into your heart. There is only one way out for you. You better take it before your filthy, abnormal, fraudulent self is bared to the nation."

"Your FBI at work," said Maddow. "That what the FBI sent to King's house with a package of tapes they said were made from the bugs they put in his bedrooms, a letter threatening him and essentially telling him to kill himself. Dr. King's wife was the person who reportedly opened that package when it arrived at their home."

"It is inspiring to see echoes of civil rights era heroism in our country today," she said. "It is unsettling to see echoes in our country today of what they fought against."

Watch the video, embedded below via MSNBC:

Visit NBCNews.com for breaking news, world news, and news about the economy