[5][6][7] Some sources have reported that Jessop had noticed school children selectively choosing leaf-covered apples that were in a well preserved in the early spring, and later grafted another variety onto it.

Though lop-sided,[8] this new cultivar quickly became popular because of its taste and long keeping properties—which were especially important in the era before refrigeration.

[10] In the early 1850s, Andrew Jackson Downing called this apple the “Imperial of Keepers” due to its excellent storage ability.

It is still commonly grown in orchards and backyards in the continental United States, especially Pennsylvania, Virginia, and North Carolina.

[5][7] In addition to its native region of south-central Pennsylvania, the 'York Imperial' is now also grown along the Shenandoah Valley and the Blue Ridge Mountains.

A bronze plaque on the medical center's lower level reads:[5][19] "THE YORK IMPERIAL APPLE Was First Propagated About 1820 In This Field By JONATHAN JESSOP It Is the Most Widely Known Variety of Pennsylvania Origin and Has Contributed Largely to the Horticultural Prosperity of the State A Tribute by The State Horticultural Association of Pennsylvania 1920"[10] A blue historical marker with yellow writing is located at South George St (SR 3001, old US 111), two miles south of York, erected on April 5, 1948, recognizing the 'York Imperial' that says “YORK IMPERIAL APPLE Here, at a nursery located on Springwood Farms, a new variety of apple was propagated by Jonathan Jessop in 1820.