Longtime Washington Nationals star Ryan Zimmerman announced his retirement Tuesday, ending a decorated career in which he became the franchise leader in many major categories and boosted the team to its only World Series championship.

Now 37, Zimmerman made it official in a public letter addressed to "Dear D.C."

CLICK HERE FOR MORE SPORTS COVERAGE ON FOXNEWS.COM

"When we first met I was a 20-year-old kid fresh out of the University of Virginia," he wrote. "I had no idea how unbelievable the next 17 years of my life were going to be."

Zimmerman was the first player drafted by the Nationals, picked fourth overall in June 2005 during their first season after moving from Montreal to Washington. He made his major league debut that September and hit .397 in 20 games, giving a glimpse of what was to come.

"Ryan will forever be Mr. National. From the walk-off home runs, to carrying the World Series trophy down Constitution Avenue, to the final day of the 2021 regular season when our fans gave him an ovation that none of us will soon forget, Ryan gave us all 17 years of amazing memories," team owner Mark Lerner said in a statement.

Washington Nationals' Ryan Zimmerman is congratulated in the dugout after hitting a two-run home run during the second inning of a spring training baseball game against the Houston Astros, Wednesday, March 24, 2021, in West Palm Beach, Fla. (AP Photo/Lynne Sladky)

Popular and productive, Zimmerman spent his entire career with Washington. He was a two-time All-Star, won a Gold Glove at third base and helped the Nationals reach the postseason five times, capped by their run to the 2019 title.

In the NL wild-card game that year, Zimmerman’s two-out, pinch-hit single off Milwaukee relief ace Josh Hader keyed a three-run rally in the eighth inning for a 4-3 victory. He later hit the first World Series homer in franchise history, connecting against Houston ace Gerrit Cole in the opener. Washington went on to win in seven games.

Zimmerman set Nationals career records for RBIs (1,061), home runs (284), hits (1,846) and games (1,799), among other marks.

He batted .277 in 16 seasons with a career .341 on-base percentage and .475 slugging percentage. He also connected for 11 walk-off homers, the seventh-highest total ever — those include a game-ending shot against the NL East rival Atlanta Braves on March 30, 2008, to win the first regular-season game at Nationals Park, the team’s new stadium.

Zimmerman became the Nationals’ third baseman in 2006 and stayed there full-time through 2013. After spending time in the outfield and infield in 2014, he took over at first base in 2015.

Zimmerman opted to sit out the pandemic-delayed 2020 season because of COVID-19 concerns.

"I have a 3-week-old baby. My mother has multiple sclerosis and is super high-risk," Zimmerman wrote in a story for The Associated Press a month before the season finally began in late July.

Zimmerman returned last year and hit .243 with 14 home runs and 46 RBIs in 110 games. His wife, Heather, gave birth to the couple’s fourth child last month.

"Although my baseball career has come to an end, my family and I will continue to be heavily involved in the DMV community," Zimmerman wrote in his retirement announcement.

"You have given so much to us over the past 17 years; it is now time for us to give back to you. We look forward to continuing many of our community programs and starting new ones in the future. Our kids will be raised here, as this is now our home, and we couldn’t be more excited. So this is not a goodbye but more of a ’see you around,’" he said.

CLICK HERE TO GET THE FOX NEWS APP

Zimmerman created the ziMS Foundation in 2006 to help those afflicted by multiple sclerosis and, with his wife, established the Pros for Heroes COVID-19 Relief Fund in 2020.

Zimmerman was nominated six times by the Nationals for the Roberto Clemente Award presented by Major League Baseball.

"Ryan’s numbers and accomplishments speak for themselves, but the way he led by example and was respected not only in our clubhouse but around the game - that is what I will remember most about his career," Nationals manager Dave Martinez said.