On Monday, we celebrated Dr. Martin Luther King’s 91st birthday. On Wednesday, Joe Biden and Kamala Harris were inaugurated as president and vice president, promising change after a dark period of division.

Dr. King’s relationship with President John F. Kennedy and President Lyndon B. Johnson offers instructive lessons for today’s movement for justice.

President Kennedy, inaugurated after eight years of Republican Dwight Eisenhower, brought new energy to Washington. He favored action on civil rights but was terribly worried that trying to move a civil rights bill would get in the way of the rest of his legislative agenda.

During his campaign, his call to Coretta Scott King when Dr. King was jailed helped him capture immense Black support in a razor-thin election.

Yet, President Kennedy was wary of Dr. King, unhappy that Dr. King and the movement kept demonstrating and forcing change. Dr. King appreciated President Kennedy but understood the conflicting pressures he faced.

The movement continued independently. The Freedom Riders in Montgomery, Ala., the dogs and water cannons in Birmingham, Ala., the sit-in in Jackson, Miss., forced President Kennedy to act. Even then the legislation — and much of President Kennedy’s agenda — was stuck in the legislature.

President Kennedy’s assassination brought then-Vice President Johnson, the master of the U.S. Senate, to the presidency.

President Johnson decided to push civil rights legislation and put his enormous skills behind passing it.

Dr. King conferred with President Johnson and helped put pressure on legislators who were reluctant. Dr. King wasn’t simply interested in protest; he wanted a change in policy and was prepared to work with LBJ to get it.

President Johnson, like President Kennedy, was wary of Dr. King. He often besmirched him in private, angry that Dr. King would not stop the demonstrations. Again, the movement — this time the dramatic scenes at Selma, Ala., — forced action, and President Johnson rose to the moment, leading to the passage of the Voting Rights Act in 1965.

The collaboration of President Johnson and Dr. King, however, soon ended. The Watts Riot angered President Johnson who thought Black people should be grateful for what he had done.

When Dr. King went public with his opposition to the Vietnam War, the relationship was severed. The FBI, under J. Edgar Hoover, continued its efforts to discredit and intimidate Dr. King.

Today the situation is different. Black voters were critical to President Biden’s election victory. He chose Kamala Harris as his vice president. He has reaffirmed his commitment to criminal justice reform, to addressing the continued disparities in education, housing, health care and opportunity.

What African-Americans still seek is an even playing field.

On economic justice issues, our agenda speaks to all: The right to a job, the right to health care, the right to a high-quality education, retirement security.

To drive reform, the lessons of the 1960s still apply. The movement for justice must continue to organize nonviolent protest, challenging the entrenched sys- temic racism that still pervades our institutions. It must continue to build, as Dr. King did, a poor people’s campaign across lines of race and region. The movement can’t follow President Biden’s timetable; it must continue to build on its own agenda.

There should be no reluctance to work with President Biden to help pass critical reforms, but at the same time, the pressure from outside must continue to build for there to be any hope of change.

The 1960s offers another caution: The war on poverty, the progress on civil rights, was lost in the jungles of Vietnam as that war consumed resources and attention as well as lives. While President Biden’s domestic pledges offer hope, he inherits a country mired in endless wars and gearing up for a new cold war with both Russia and China. Once more, follies abroad may sap the energy needed to rebuild at home.

Once more, the movement for justice must not be silent about the administration’s priorities. President Biden’s inauguration offers new hope and new energy. He inherits severe crises — the pandemic, mass unemployment, extreme inequality, the climate crisis, racial upheaval. He’ll need all the help he can get. And the best way the movement can help is to keep on keeping on.

The writer is founder and president of the National Rainbow PUSH Coalition.