 Upon the opening of the Ohio and Mississippi Railroad to St Louis in 1854 (this being the first railway to reach St Louis from the East) Captain Flad went to Missouri as an assistant engineer on the Iron Mountain Railroad, of which his former colleague on the Erie Railroad, Mr. James H. Morley, was the chief engineer.During the construction of this road Captain Flad was located at Potosi, Missouri.After its completion to Pilot Knob, where for a number of years it ended, he became land and tie agent of the railroad company, with headquarters at Arcadia, Missouri.