American Flyer was on of the first American wide gauge toy train company's, I think they predate Lionel, who chose to call his track Standard gauge, though I believe it is the same size, just Lionel had better marketing.
Lionel was the first to produce that gauge and called it Standard Gauge. Lionel began producing it sometime in the early 1900s. I believe Lionel first introduced 2 7/8 gauge trains and then went to Standard Gauge, which is slightly smaller (is it 2 1/4 gauge?). At the time Lionel started producing Standard Gauge, other manufacturers were making 0,1, 2, 2 7/8, & 3 gauge (and possibly other sizes, I am not an expert on the sizes). Lionel started making Standard Gauge and for whatever reasons, it took off and other manufacturers began to make trains in Standard/Wide Gauge.
American Flyer began making O gauge windup trains in 1907 and brought out O gauge electric trains in or around 1918. American Flyer introduced Wide Gauge in 1925. I believe American Flyer "killed" standard gauge around 1933-1934 and continued to catalog unsold items through 1936.
Additionally, Lionel was the last company (in the prewar era) to discontinue Wide Gauge, which I believe it did in 1939.
NWL