Which former U.S. Attorney for Washington, D.C. became the first African American U.S. Attorney General in 2009?

Which 2009 film stars Denzel Washington as a New York City subway dispatcher facing a train hijacking? In Swahili, a "nyumba ya posta" is a place to send a "barua", or letter. What is it? What is the name for a 1 followed by 100 zeros? A one-time gag writer for Red Skelton, who was reportedly TV's highest-paid star at his peak in the 1980s? Which downtown Los Angeles arena, opened in 1999 and home to the Lakers, was renamed Crypto.com Arena in 2021? A Civil War general who had been reduced to lieutenant colonel, who died at Little Bighorn in 1876? A Pacific bluefin, one of which fish, was tracked swimming 6,700 miles from Japan to Baja California? A Packard touring car disguised as a police car was used in which 1929 holiday killing in Chicago?