On this day, April 6 …

2019: Former President Barack Obama says, at an Obama Foundation event in Berlin, Germany, that he is worried that progressives are creating a "circular firing squad" as prospective Democratic presidential candidates race to the left on a number of hot topic issues ahead of the 2020 election.

Also on this day:

1830: The Church of Jesus Christ of Latter-day Saints is organized by Joseph Smith in Fayette, N.Y.

The Church of Jesus Christ of Latter-day Saints is organized by Joseph Smith in Fayette, N.Y. 1896: The first modern Olympic games formally opens in Athens, Greece.

The first modern Olympic games formally opens in Athens, Greece. 1909: American explorers Robert E. Peary and Matthew A. Henson and four Inuits become the first men to reach the North Pole.

American explorers Robert E. Peary and Matthew A. Henson and four Inuits become the first men to reach the North Pole. 1917: The United States enters World War I as the House joins the Senate in approving a declaration of war against Germany that is then signed by President Woodrow Wilson.

The United States enters World War I as the House joins the Senate in approving a declaration of war against Germany that is then signed by President Woodrow Wilson. 1954: Sen. Joseph R. McCarthy, R-Wis., responding to CBS newsman Edward R. Murrow’s broadside against him on “See It Now,” says in remarks filmed for the program that Murrow has, in the past, “engaged in propaganda for Communist causes.”

Sen. Joseph R. McCarthy, R-Wis., responding to CBS newsman Edward R. Murrow’s broadside against him on “See It Now,” says in remarks filmed for the program that Murrow has, in the past, “engaged in propaganda for Communist causes.” 1965: The United States launches the Intelsat I, also known as the “Early Bird” communications satellite, into geosynchronous orbit.

The United States launches the Intelsat I, also known as the “Early Bird” communications satellite, into geosynchronous orbit. 1971: Russian-born composer Igor Stravinsky, 88, dies in New York City.

Russian-born composer Igor Stravinsky, 88, dies in New York City. 1973: Ron Blomberg of the New York Yankees becomes Major League Baseball’s first designated hitter as he faces pitcher Luis Tiant of the Boston Red Sox at Fenway.

Ron Blomberg of the New York Yankees becomes Major League Baseball’s first designated hitter as he faces pitcher Luis Tiant of the Boston Red Sox at Fenway. 1994: Supreme Court Justice Harry A. Blackmun announces his retirement after 24 years.

Supreme Court Justice Harry A. Blackmun announces his retirement after 24 years. 1998: The Dow Jones Industrial Average closes above 9,000 points for the first time, ending the day at 9,033.23.

The Dow Jones Industrial Average closes above 9,000 points for the first time, ending the day at 9,033.23. 1998: Country singer Tammy Wynette dies at her Nashville, Tenn., home at age 55.

Country singer Tammy Wynette dies at her Nashville, Tenn., home at age 55. 2009: Michael Jordan, and former Dream Team teammates David Robinson and John Stockton, are elected to the Basketball Hall of Fame; Utah Jazz coach Jerry Sloan and Rutgers women’s coach C. Vivian Stringer are also part of the class.