You posted in that other thread. Then out of the blue youtube gives me that Erie canal story, followed by the Mississippi, and Transcontinental railroad stories. It was like bingo, and fell into place nicely. I had such a good morning watching those three videos above from a "Sunday Morning" program that I enjoy from time to time, and I will take a look at your links when I have a more alert moment than current.
Had a long day shopping for things for hobby terrain at Lowe's and Michael's, plus a sojourn to a hobby store where I picked up ... some things. Will share more elsewhere at some point.