She completed her journey on September 16 in Los Angeles, at the home of the Angels. It was stop number 30.

Hailey was born in Nevada in 2010 with Poland syndrome, a genetic condition that stops development of muscles on one side of the body. Hailey was born without a right pectoral muscle and with only two fingers on her right hand: thumb and little finger. Hailey's mother, Yong Dawson, got in touch with engineers at the University of Nevada, Las Vegas, who used a 3D printer to generate a robotic hand for Hailey.

Hailey's prosthetic hand is made from a special kind of plastic called acrylonitrile butadiene styrene (ABS). It is used in many everyday items, including musical instruments, luggage, and LEGO bricks. The joints of Hailey's hand are held together with rubber and fishing wire. Altogether, the hand has 30 parts. It runs not on electronics but on Hailey's own movements. When she flexes her wrist, the fingers grip; extending her wrist makes the fingers uncurl. Velcro straps keep the hand on her wrist.

She got the 3D-printed hand when she was 4. Skeptical at first, she soon embraced her newfound abilities. And along the way to delivering that 30th first pitch, she jumped into the world of social media. Now, Hailey (or, more accurately, her hand) is represented on Facebook, Instagram, and Twitter, with such empowering messages as this one: "Self-confidence is the best outfit. Rock it and own it!"

Hailey started her tour of baseball stadiums in 2015, with the first pitch at the home of the UNLV Rebels. That same year, her family got in touch with the Baltimore Orioles–the favorite team of her father, Greg–and told her story; not long after, she threw out the first pitch at Oriole Park. Two years later, she threw out the first pitch at the home of the Washington Nationals. Hailey was especially pleased with this assignment because a star player for the Nationals is Las Vegas native Bryce Harper, Hailey's favorite player.

A story that ran in national sports media brought attention to Hailey's story, and then she and her family (including cheerleader and older brother, Zach, himself a baseball player and fan) created the Journey to 30, the quest to appear at all Major League ballparks. Hailey and her family–her mother, especially–wanted to raise awareness for people who have Hailey's condition and also for others who need (and perhaps cannot afford) prosthetics.

A high-profile stint throwing out the first pitch during the 2017 World Series added exposure to Hailey's quest. United Airlines chipped in with an offer to provide air transport to help Hailey along the way. And for each game, the engineers at UNLV printed for Hailey a new hand sporting the team colors of the home team at which she would deliver the first pitch. Each hand sported a Hailey-requested cover that she has used to collect autographs of baseball players.

Throwing out the first pitch at a baseball park is a common enough occurrence. It's a ceremonial part of the pregame ceremonies at nearly every baseball game, not only at the major league level but also at minor league and college parks. A few people may do it more than once. But few have done it with any regularity. And no one has come close to doing what Hailey Dawson has now done, at age 8, with a prosthetic hand.

Her honors extend beyond baseball diamonds:

• In February 2018, she dropped the puck at a professional hockey game between her local team, the Vegas Golden Knights, and the Philadelphia Flyers. Wearing a Golden Knights jersey, she also sported a 3D-printed hand sporting Golden Knights colors.
• Also in February 2018, she was given the Baseball Ambassador Award by the Las Vegas Chapter of the Society for American Baseball Research.
• In 2016, she toured the White House and met then-President Barack Obama. On her hand that day was the seal of the President of the United States.