President Lyndon B. Johnson and Dr. Martin Luther King Jr. shared a deep, personal, and practical relationship that helped in passing 1960s civil rights legislation, panelists said Wednesday as part of the LBJ Presidential Library Civil Rights Summit.

“I think it was very warm and personal,” said former Rep. Andrew Young, a close King aide, describing the relationship between King and Johnson. “Whenever I was with them there was never an argument or tension; there was gentlemen’s disagreement. Dr. King saw himself as having to keep the pressure on.”

Pressure created by the March on Washington and nonviolent civil rights demonstrations in the South—and authorities’ often brutal crackdowns on them—began to open the door to major civil rights legislation in 1963, but it took leadership from Johnson and congressional leaders to push it through the following year, speakers said.

That legislation, the landmark Civil Rights Act of 1964, is the focus of the three-day summit, which is bringing four of the five living U.S. presidents and numerous other leaders to Austin to discuss past and current civil rights issues.

The “LBJ and MLK” panel featured speakers who either worked with or extensively studied Johnson, including historian Taylor Branch; author Doris Kearns Goodwin, a former LBJ aide; Joseph Califano Jr., former U.S. Army general counsel who was Johnson’s top domestic aide; and moderator Todd Purdum, a journalist and author of “An Idea Whose Time Has Come,” a new book about the Civil Rights Act. Young, who went on to serve as a United Nations ambassador and Atlanta mayor, offered perspective from the movement’s front lines.

The speakers agreed that although Johnson initially called for passage of the Civil Rights Act in honor of the recently slain President John F. Kennedy, he quickly made the issue his own and did everything in his power to see it through Congress, even at the risk of alienating fellow Southern Democrats.

“Within a month after Johnson became president, the government changed,” Califano said. “The pressure to do civil rights…it was in his gut.”

Johnson’s later civil rights achievements, including the Civil Rights Act of 1964 and the Voting Rights Act of 1965, were his proudest, Goodwin said.

“And he knew it would stand the test of time,” she said.

The session began with the playing of a recorded phone conversation between King and Johnson in which they pledged cooperation, although their relationship was not without conflict. Goodwin said tension is inevitable when an outside movement is pushing a president to act more quickly than the government is prepared to act.

“The same tension existed between Lincoln and Frederick Douglass,” said Goodwin, author of the 2005 Lincoln biography "Team of Rivals." “Douglass was constantly telling him, ‘You’re not doing everything I want you to do,’ and eventually they became really good friends. And Lincoln understood he needed Frederick Douglass and the abolitionists, just as LBJ needed the civil rights movement. And together Martin Luther King and LBJ produced something—thank God they were there at that moment of history—that changed our country forever.”

The Civil Rights Act was the gateway to broader freedoms for many other Americans, including women and the disabled, Branch said.

“All those doors opened in the wake of going through the gate of race,” Branch said, adding that he viewed civil rights leaders as akin to founding fathers. “They were confronting subjugation and they were setting in motion equal citizenship.”