It is possible that only among university scholars was this "denial" ever present: I've heard people discuss their southern and midwestern Irish ancestors (both Catholic and Protestant) with a casualness that suggests little belief that these non-urban relatives were in any way unusual.
There is also the variety of economic circumstances for the Irish in America to consider, including the role of Irish industrial workers outside of northern cities--say, in places like the south. A few weeks ago, organizers of a significant project under way here in Virginia to recover the history surrounding 19th-century Irish workers on the Blue Ridge railroad tunnels presented some of their preliminary finds to the Irish American Society of Great Richmond.The tunnel project was a major engineering feat led by the French engineer Claudius Crozet for the Blue Ridge Railroad and designed to allow train traffic from Charlottesville to Staunton through the heart of Virginia's mountains. Four tunnels were completed during the 1850s using a combination of slave and Irish labor, the longest of which, at Afton, VA, extended over 4,200 feet. As Dan Burke, one of the project leaders, so vividly explained, tunneling in the last waning years prior to nitroglycerin and dynamite continued to involve extremely labor-intensive approaches: boring holes in solid rock using drill bit and hammers (a two man job), placing blackpowder charges, and blasting out rock at the rate of a few feet a month. The image the most struck me, however, was that of the nearby labor camps that were closed down once the tunnels were finished, leaving little historical evidence aside from the cut rock itself that so many laborers had been anonymously at work before casually moving on to employment elsewhere.
The team at work on this project, Clann Mhór, has combined public education and historical advocacy in a very nice way. Not only are they recovering as much of the evidence about the lives of these workers as possible from from company and church records, census information, and citizenship applications, but because the Afton tunnel is being returned to use after 70 years as part of a Rails to Trail project, they are also using their research to put together commemorative and educational markers at the site. The progress of Clann Mhór can be followed here, and you might want to check out some nice images by way of DailyProgress.com for a sense of the Rails to Trails work.