Milestones

MARKED

By President Obama and more than 100 members of Congress, the 50th anniversary of the “Bloody Sunday” march out of Selma, Ala. Tens of thousands walked across the bridge that was the scene of one of the most iconic moments of the civil rights movement.

SUED

By the parent company of Wikipedia and other groups, the National Security Agency and the Department of Justice. The groups say an NSA mass-surveillance program violates the Constitution.

DIED

Blogger Lisa Bonchek Adams, 45, who built a devoted readership through frequent, heartfelt tweets and posts about her struggle with breast cancer.

DIED

Documentarian Albert Maysles, 88. Alongside his brother, he made Gimme Shelter, about the Rolling Stones, and Grey Gardens, about eccentric relatives of Jacqueline Kennedy Onassis.

DIED

Journalist Claude Sitton, 89, who covered the civil rights movement in the 1950s and ’60s and later won a Pulitzer Prize for commentary.

DISCOVERED

How chameleons change their color. Researchers found that pigment cells expand and contract around crystals to reflect different levels of light.