- About PRO
1996 - The first Major League Soccer season.
2012, March - U.S. Soccer and MLS created PRO.
2012, March - Peter Walton was appointed PRO General Manager.
2012, October - www.proreferees.com was launched.
2013 - The 100th referee since the inception of Major League Soccer in 1996 officiated an MLS fixture.
2013, March - First full MLS season with PRO involvement kicked-off.