WASHINGTON (AP) — President Barack Obama saluted Dr. Martin Luther King Jr. Sunday as a man who “stirred our conscience” and made the Union “more perfect,” rejoicing in the dedication of a monument memorializing the slain civil rights leader’s life and work.

“I know we will overcome,” Obama proclaimed, standing by the 30-foot granite monument to King on the National Mall. “I know this,” the president said, “because of the man towering over us.”

Obama and his wife, Michelle, and Vice President Joe Biden and his wife, Jill, joined a host of civil rights figures for the dedication on the sun-splashed Mall. Designed as what King described as a stone of hope hewn from a mountain of despair, the memorial is the first to a black man on the National Mall and its parks.