In what part of North America is the climate most favorable for the life and economic activities of the population?

It is easy to determine if you look at the map and calculate where the highest area of the population is.
These include California, the entire eastern United States (from New Orleans to Boston), and between Iowa and the Atlantic coast.
In addition, the southern part of Canada, especially the strip between Winnipeg and Quebec.
These territories were developed back in the 17th-19th centuries (later all California). They have a high density of population and economic objects – production, agriculture, logistics and business centers.