Former United States Representative John Conyers Jr., the longest-serving African American congressman in history, died at his home on Sunday. He was 90. 

Detroit police spokesman Cpl. Dan Donakowski believes that his death "looks like natural causes," NBC News reports. Conyers Jr. was first elected in 1964 after winning his election by a mere 106 votes. His victory propelled him into rarefied air at the time, making him one of only six African American members of the House. 

Just a few years after his first election win, Conyers Jr. helped spearhead an initiative to make Dr. Martin Luther King Jr.'s birthday a national holiday shortly after his assassination in 1968. His efforts were exhaustive, but ultimately rewarding when then-President Ronald Reagan signed a bill into law in 1983 declaring the creation of Martin Luther King Jr. Day, which would be first observed three years later. 

In 1971, Conyers Jr. helped found the Congressional Black Caucus. Three years later, as a member of the House Judiciary Committee, he pushed for the impeachment of Richard Nixon over Watergate, arguing that his ousting was necessary to "restore to our government the proper balance of constitutional power and to serve notice on all future presidents that such abuse of power will never again be tolerated.” His remarks still feel pertinent in this current political climate under this administration. 

Conyers Jr. was pushed into stepping down in 2017 amid accusations of sexual misconduct by two women. Despite always denying the allegations, he still resigned.

Various notable people in the world of politics and beyond reacted to Conyers' death.