i've got a coupla old books on bicycles, and according to one, S.H. Roper built the first steam powered bicycle in the late 1860's.
in 1894, E.J. Pennington introduced the "Motor Cycle" with a 10lb kerosene engine.
around 1900, an unknown american developed the "Gun Powder Bike," which supposedly could do 100mph when lit.
in 1898, the Waltham Manufacturing Co. of Massachusetts introduced the first successful line of "motor cycles" based on their popular "Orient" bicycle.
then came Harley Davidson and the Hendee Manufacturing Co. (maker of the Indian,) Curtiss, and all the rest about the same time.
the first casualty is thought to be Frank A. Elwell, (a bicycling pioneer who toured America, Asia and Europe,) who broke his neck when his forks collapsed in 1902.