He has lofty goals set and hopes to be sent to Vermont or Hagerstown following the Rookie League short season.
Financial terms of the contract were not disclosed by the Nationals at the signing, but it is believed King received a $250,000 signing bonus along with a generous financial agreement pertaining to college.
King was signed by Mid-Atlantic scout Alex Smith.
"I've watched (Brandon) since I first saw him three years ago," said Smith. "My associate (Mike Conway) always kept me abreast of Brandon. He is a physical presence with arm strength.
"He had some physical issues (sports hernia), pitched through it last year and put any issues aside this year," said Smith. "We got film of him to the team scouting department and they bought into Brandon."
King was drafted in the 27th round of the major league baseball draft, but the signing bonus indicates the Nationals have a high regard for the 6-foot-4, 230-pound righthander.
That was enough to get King to forego his the start of his college education.
"If (Brandon) walks away from the game he can go to any four-year college and the Nationals will provide complete aid for eight semesters," said Tim King, Brandon's father.
Last week, the King's were returning home from a visit at Penn State when Smith called. On Thursday, they drove to meet with Smith in Abington, Md. for a contract offer. On Friday, an upgraded offer was made and a decision to sign was reached Saturday.
"The offer really made me think about going pro," Brandon King said. "They included education in the contract and that made up my mind."
King garnered the Herald-Mail Hitter of the Year award and capped off his awards collection with the West Virginia Player of the Year honors.
King led Martinsburg to the Class AAA state championship while hitting .454 with huge power numbers. He had 15 home runs and 12 doubles among his 54 hits and drove in 55 runs. On the mound, he went 8-2 with a 1.53 earned run average and 72 strikeouts in 55 innings.