I'm not an expert on the colonisation of North America, but I did a little research (and you should too - you should have been explained the contexts).
The challenges were mainly connected with building infrastructure,. The climate is benign, the land is fertile. There is plenty of water for irrigation (and to drink).
There would have been land use issues between agriculture, horticulture and industry, but these seem to have resolved themselves very early in the process.
So, challenges were few. (In terms of geography and climate).