He batted .335 and hit five home runs in 2013 and led Richland with a .443 on-base percentage and 17 doubles.
A shortstop, Blanton joins an organization that has young talent at the position in rookie Adeiny Hechavarria and 2012 third-rounder Avery Romero.
Blanton will aim to emulate the path to the Majors taken by the Marlins' 2008 ninth-round selection -- left-handed reliever Dan Jennings.
Since making his MLB debut in April 2012, Jennings has a 1.88 ERA in 28 appearances out of the bullpen.
Joe Morgan is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.