As wikipedia has it:
In 1816 a wealthy Englishman named George Flower came to America. He and another Englishman, Morris Birkbeck met and agreed to explore the western country with the idea of starting a colony of their own countrymen. After a long voyage of prospection through Ohio, Indiana, and the Illinois Territory, they were so impressed with the beauty they saw in the countryside when they reached Boultinghouse Prairie, they knew they had found the site for which they were searching. They soon bought up all the land they could afford, and eventually brought over from England more than 200 settlers, £100,000 in capital, and a carefully thought out selection of good livestock and agricultural implements: the area became known as the English Settlement.
It seems two wealthy Englishmen, Birkbeck and Flowers, became interested in the U.S. and disgusted with post-Napoleon England. So they visited the U.S., selected southeastern IL as the place to settle, wrote books on the U.S. and the opportunities, bought land, brought over settlers, split irrevocably, perhaps over love of the same woman, founded separate towns, Albion IL and a failed town, and then died. Lots of people visited them and wrote their opinions of the effort, pro and con. The book is a selection of writings from Birkbeck and Flowers plus those who wrote about their efforts.
It presents an interesting picture of the Illinois prairie country, roughly on the same latitude as Perry County where the Harshaws settled but 20 years earlier and miles further east What struck me was the extensive use of liquor. It may explain Rev. Michael Harshaw's firm temperance views.