Double-decker bus
The first commercial horse-drawn double-decker omnibuses were introduced in England in 1847 by Adams & Co. of Fairfield, Bow, then improved upon by John Greenwood, who introduced a new double-decker in 1852.
Double-decker bus
Also in Los Angeles, SCRTD used Neoplan AN 122/3 Skyliners double-decker buses from the late 70s until 1993.