I'll try to clairfy this for everyone.
In the late 80s,early 90s, Roadway tried to copy what CF had done with Conway. They had 4 regional operation units covering the entire country. There was Coles Express in the Northeast, Spartan Express in the Southeast, Central Freight in the Southwest and Viking in the West and Northwest.
These 4 compaines were eventually merged together under the Viking name and it was a HUGE failure. Coles and Spartan were closed, Central was sold off to managemt and Viking remained.
I don't remember the exact timeline but somewhere along the line Caliber Systems was formed as the holding company for these companies and was spun off from Roadway.
When all the dust settled, Caliber was left with Viking Freight, Roberts Express, Caliber Logistics and RPS(Roadway Package System).
In 1998, FedEx bought Caliber Systems. Viking Freight remained the same. Roberts Express was rebranded FedEx Custom Critical, RPS was rebranded FedEX Ground and I'm not sure what became of the logistics unit. I assume it got folded into FedEx.
In 2001, FedEx completed the purchase of American Freightways which went on to be rebranded FedEx Freight along with Viking.
As for Motor Cargo, They were bought by Neither UPRR or Overnite. They were bought by Overnite Holdings company which was a division of Union Pacific. Overnite Holdings was formed just before the purchase of MC to be a the parent company of both Overnite and MC