Today, just after 1:05 p.m., Aerosmith’s Steven Tyler will sing the national anthem before Pedro Martinez throws the first pitch of the 2002 Boston Red Sox season. In most years, the anthem would be an afterthought, a brief formality preceding each of the season’s 162 games. But last year, when baseball resumed after Sept. 11, the tension in the air during the anthem was palpable. Especially during the World Series, as military action had begun in Afghanistan, Francis Scott Key’s dramatic lyrics had renewed significance for generations of Americans.

In this day of guaranteed contracts and a minimum major league salary of $200,000, it is difficult to imagine pampered ballplayers leaving their lucrative profession to fight for America. Yet, throughout baseball’s history they have done just that, risking death and career-ending injury to serve the United States.

By the end of 1917, less than a year after the U.S. had entered World War I, 15 Red Sox players were already in the military. By the end of the war, almost 250 players were serving, and many were on the battlefield in Europe. Christy Mathewson, a Hall of Fame pitcher and manager of the Cincinnatti Reds, was one of many who enlisted in the army. Mathewson died seven years later, after developing tuberculosis from poison gas.

During World War II, many of baseball’s greatest hitters and pitchers were absent from the diamond. According to The New York Times, 5,400 of the 5,800 ballplayers at the end of 1941 were in the military by January of 1945. Detroit Tigers slugger and American League Most Valuable Player Hank Greenberg entered the army on May 7, 1941, the day after he hit two home runs against the Yankees and seven months before Pearl Harbor. The season of 1941 was a magical one; Ted Williams hit .406 and Joe DiMaggio hit safely in 56 straight games. By 1943 both were in uniform, spending three years in the prime of their careers serving a calling higher than baseball.

Williams, the greatest hitter that ever lived, went on to fly combat missions in Korea. Jerry Coleman, a star second baseman for the Yankees, flew 57 missions in World War II and 63 in Korea. They were two of more than 120 ballplayers who served in the Korean War.

Those who were ineligible for military service often tried to help in other ways. Tony Conigliaro, the star-crossed Red Sox outfielder who was the youngest player in Major League history to win a home run title and the youngest to reach 100 career home runs, visited hospitals in Vietnam with Coleman during the winter of 1967. Earlier that year, Conigliaro had been hit in the face by a pitch—an injury that impaired his eyesight and from which he never fully recovered. In 1942, 47-year-old Babe Ruth walked to the plate to face 54-year-old Walter Johnson, one of the greatest pitchers to ever play the game, in a home run hitting contest that raised $80,000 for the Army-Navy relief fund.

There are thousands more stories of players whose careers and whose lives were cut short defending America. So this year, as American troops are fighting in Afghanistan—and perhaps soon, in Iraq as well—the national anthem, and the sight of the stars and stripes whipping in the fresh spring wind, should remind every fan of the sacrifices others made, and are making to protect the land of the free and the home of the brave.