He has almost grown up under the microscope, appearing on the cover of Sports Illustrated at the age of 16. Harper, who won't turn 19 until October, attended high school for just two years, received his general equivalency diploma, and played last year in junior college.
He batted .443 with 31 home runs and 98 RBIs as a freshman for the College of Southern Nevada last year before being the first overall pick.
Now a member of the low- single-A Hagerstown Suns, Harper made his first local appearance, beginning a weekend series on Friday against the Lakewood BlueClaws, a Phillies affiliate.
A former catcher, the 6-foot-3, 225-pound Harper is playing right field for the Suns and has treated professional pitching in the same dominating manner he did in high school and junior college.
After going 1 for 4 to extend his hitting streak to 17 games in Friday's 4-3 win over Lakewood, Harper was batting .390 (46 for 118) with eight home runs and 30 RBIs.
"Nobody has seen an 18-year-old who can do some of the things he is doing," said Suns hitting coach Marlon Anderson, the former Phillies infielder. "He should be in high school getting ready to graduate, but he is out here hitting bombs all over the place."
Speaking before Friday's game against Lakewood, Anderson said that despite all the hype - which has come from that sweet, lefthanded swing; excellent speed; and a cannon arm - there is one simple thing that people forget about Harper: He is the same as any 18-year-old, other than his earning power.
"His teammates rip him and give him a hard time just like anybody else, and that is good for him being around guys who are around his age," Anderson said. "This is great for him to be here, but I don't know how long he will be here."
The Nationals aren't tipping their hand concerning their plans for Harper.
