Speaking of invasive plants, I recently learned that white poplar trees are not endemic to the U.S., but, instead, brought over in 1748. See
https://en.wikipedia.org/wiki/Populus_alba .
As a child, I vacationed in Lac Du Flambeau, Wisconsin, which had many white poplar trees growing near lake shores (the only other white trees were birch). Of course, I assumed that those trees belonged there so now it is a big surprise (almost a shock) to learn that they didn't.