North America got a lot more colonists than Mexico and also got them a lot sooner after the first significant contact was made. Mexico City was conquered in 152

North America got a lot more colonists than Mexico and also got them a lot sooner after the first significant contact was made. Mexico City was conquered in 1521 and New Spain received 1-1.5 million colonists (including slaves) before independence in 1810. In North America the first colony was Roanoke in 1584 (only including English colonies and this failed one for simplicity) and had 2.4 million settlers by 1788. So in Mexico the population had more time to bounce back and less of a European influx to contend with. South America also had a lot less colonists (Portugal only had 2 million people and tried to restrict emigration) they also received a lot more slaves (North America got <10% of the slave trade) which mixed with with the native population.