AUSTIN, Tex. — Luci Baines Johnson leaned forward in her father’s private suite at the L.B.J. Presidential Library, her voice breaking as she recounted the “agony of Vietnam” that engulfed Lyndon Baines Johnson and the pain she feels to this day of witnessing his presidency judged through the prism of a failed war.

“Nobody wanted that war less than Lyndon Johnson,” said Ms. Johnson, 66, who is the president’s younger daughter. “No matter how hard he tried, he didn’t seem to be able to get out of that quagmire. Not only did he not get out of it in his lifetime, but his legacy indeed has that weight of the world on it.”

But now, 50 years later — with a coming rush of anniversaries of the legislative milestones of the Johnson presidency — Ms. Johnson and the diminishing circle of family and friends from those White House years have commenced one last campaign. They are seeking a reconsideration of Johnson’s legacy as president, arguing that it has been overwhelmed by the tragedy of the Vietnam War, and has failed to take into account the blizzard of domestic legislation enacted in the five years Johnson was in the White House.

On Monday, the L.B.J. Presidential Library and Museum will announce details of a Civil Rights Summit to be held here in April to commemorate Johnson’s signing of the Civil Rights Act, attended by three of the four living former presidents — Jimmy Carter, Bill Clinton and George W. Bush — and perhaps President Obama.