In 1835, it was a rather different story.
When Chicago was incorporated in 1833 it had a population of just 350 souls. It grew rapidly, however, and according to the US Census was home to 4470 people in 1840. We're a little data-constrained on the Irish side of the pond because the first census wasn't gathered until 1841. Then we had The Famine in 1845/6/7 and another census in 1851, so we'll have to extrapolate and guesstimate a bit to reveal the population of the valley in, say, 1835. The population of the Co. Carlow parish of Kiltennell, which included Knockroe, Coonogue and 17 other townlands lost a third of its people (3,544 to 2,454) during the sear and sorry 1840s. You can still see the ridges of the lazy-bed potato fields 1000ft up above the valley.
From the data in the table above, we can show that in 1833 and possibly as late as 1836, there were more people living in and off the Scullogh Gap than in the city of Chicago.
Not a lot of people know that.