Before 1898, the largest population bump from annexation came from the lands wrested from Mexico (including Texas) between 1845 and 1853. Yet, as bumps go, it wasn’t much. While those accessions enlarged the country’s area by 69 percent, the accompanying Indians and Mexicans increased its population by less than 1.5 percent over eight years. In the demographically explosive United States, where the population was already growing at more than 3 percent a year, that small influx was easily diluted: a sprinkler in a rainstorm.
