Johnson's daughter, Carolyn Johnson-Thomas, was on hand to watch her very first game since baseball returned to Washington in 2005. The 84-year-old may not be at the games, but she does follow the team daily.
"I watch all the games on television," she said. "I have all sorts of opinions about them."
She was joined by her son, Hank Thomas, who wrote a book about the life of his grandfather. Thomas called Johnson's debut "one of the great moments in Senators history."
He was invited to throw out out the first pitch before the game, and delivered a chest-high strike to manager Manny Acta.
The day was named "Walter Johnson Day" at RFK Stadium, and the Nationals wore caps from the era when Johnson pitched -- white with a block "W" and red bill.
Johnson's past was celebrated as the team announced plans to memorialize him in the new ballpark, which will be ready for Opening Day 2008. Principal owner Mark Lerner joined Johnson-Thomas in unveiling a plaque that will go on display at the new park. In addition, the team will commission three statues to go on display outside the stadium: Johnson, Negro Leagues star Josh Gibson and Frank "Hondo" Howard, an outfielder with the Senators.
After the ceremony, the team unveiled a banner in left field at RFK Stadium that will count down the games remaining in the stadium. As of Thursday, there were 26 home games remaining.
Other "Walter Johnson Day" festivities included a video that was played of his achievements, celebrating his "incredible speed and wholesome demeanor."
Johnson's career spanned three decades, all of them in Washington. During that time he won 417 games, the second-most in baseball history. He was a part of the only Washington team that won a World Series, taking the title in seven games in 1924.
Michael Phillips is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.