Ontario was founded on June 11, 1883, by developers William Morfitt, Mary Richardson, Daniel Smith, and James Virtue. In March 1884, Richard Welch started a post office for the quarter of Ontario, so named by James Virtue after Ontario, Canada. Two months later Joseph Morton applied for a Morton post office at an island about one mile south of town, with Oscar Scott as postmaster. Unfortunately for Morton and Scott, merchants Morfitt and Richardson of Malheur City, gold miner Virtue, and lumberman Smith of Baker City acquired more land and were better financed. More importantly, Morfitt had negotiated a train depot for Ontario. All the settlers and speculators knew the railroad was coming and how important that would be to Ontario's future so Scott closed his Morton post office and built a hotel at present-day Ontario. By December, Scott was Ontario's postmaster.