EXACTLY 125 years ago today , about 2:40 p.m. , three lawmen -- Marshal Virgil Earp and his brothers Wyatt and Morgan -- and their friend Doc Holliday walked down Fremont Street , today Highway 80 , in the silver-mining boom town of Tombstone , Ariz. , and into a lot behind the O.K . Corral to confront four '' cow-boys '' -LRB- as cattle thieves were then called -RRB- , the brothers Ike Clanton and Billy Clanton and Tom McLaury and Frank McLaury .