Grand Canyon

A lookout instrument along the South Rim of the Grand Canyon National Park in Arizona is shown Thursday, Feb. 26, 2009. The park was established as a national park on Feb. 26, 1919.

In 1904: The United States and Panama proclaimed a treaty under which the U.S. agreed to undertake efforts to build a ship canal across the Panama isthmus.

In 1940: The United States Air Defense Command was created.

In 1942: “How Green Was My Valley” won the Academy Award for Best Picture of 1941, beating out nine other films, including “The Maltese Falcon” and “Citizen Kane.”

In 1945: Authorities ordered a midnight curfew at nightclubs, bars and other places of entertainment across the nation.

In 1952: Prime Minister Winston Churchill announced that Britain had developed its own atomic bomb.

In 1966: South Korean troops sent to fight in the Vietnam War massacred at least 380 civilians in Go Dai hamlet.

In 1984: The last U.S. Marines deployed to Beirut as part of an international peacekeeping force withdrew from the Lebanese capital.

In 1994: A jury in San Antonio acquitted 11 followers of David Koresh of murder, rejecting claims they had ambushed federal agents; five were convicted of voluntary manslaughter.

In 1998: A jury in Amarillo, Texas, rejected an $11 million lawsuit brought by Texas cattlemen who blamed Oprah Winfrey’s talk show for a price fall after a segment on food safety that included a discussion about mad cow disease.

In 2014: Republican Arizona Gov. Jan Brewer vetoed a bill pushed by social conservatives that would have allowed people with sincerely held religious beliefs to refuse to serve gays.

In 2017: At the 89th Academy Awards, “Moonlight,” an LGBT coming of age drama, won three Oscars, including best picture of 2016 (in a startling gaffe, the musical “La La Land” was mistakenly announced as the best picture winner before the error was corrected).

In 2019: After making his way from Pyongyang in an armored train, North Korean leader Kim Jong Un arrived in Vietnam’s capital ahead of a summit with President Donald Trump, who arrived later in the day aboard Air Force One.

Ten years ago: In a statement, President Barack Obama said Moammar Gadhafi had lost his legitimacy to rule and urged the Libyan leader to leave power immediately. Space shuttle Discovery arrived at the International Space Station, making its final visit before being parked at a museum.

Five years ago: New Jersey Gov. Chris Christie stunned the Republican establishment by endorsing Donald Trump for president.

One year ago: President Donald Trump declared that the U.S. was “very, very ready” for whatever threat the coronavirus would bring; he put Vice President Mike Pence in charge of overseeing the country’s response. The World Health Organization reported that the number of new coronavirus cases outside China had exceeded the number of new infections in China for the first time. Brazil’s government confirmed the first case of the coronavirus in Latin America; a 61-year-old man who had traveled to Italy had tested positive. Facebook said it was banning ads that made false claims about products tied to the coronavirus. As Christians around the world marked the start of Lent with Ash Wednesday, worshipers found churches closed and rituals changed by virus fears. An employee at a Wisconsin brewery opened fire on co-workers, killing five of them before taking his own life. Maria Sharapova retired from professional tennis at the age of 32, after a career that included five Grand Slam titles.