People lived longer in the Northern than in the Southern colonies. One reason was diet: tons of lentils and beans and abstemious Puritan veg up north, plus hard water (minerals); down south, hams and cookery with lots of sauces to clog the arteries, starchy foods and low-mineral soft water, plus warmer ambient temperatures more nearly ideal for incubating things that would kill you or make you sick.
An offshore drilling contractor acutely interested in reducing communicable disease in their living quarters found that setting the A/C to 66 degrees F greatly reduced common medical complaints like colds, flu, assorted kinds of The Crud. At that temperature, their onboard safety/health officer explained to me, common pathogens are a lot less active than at the mid-70's daily low temps that are the rule in the South in summer. (Last night, the 10:30 PM temperature in Houston was 84F, the low predicted to fall in the upper 70's.) Sounds like a key to me.
Life expectancy was such in the colonial South that English colonists who got married (the men usually waiting until their 30's -- as opposed to teens or early 20's in Puritan, kick-'em-out-young New England) could only expect an average of seven (7) years of married life together "until death do them part". This had consequences -- the South has always featured larger, "blended" families, step-relations, and uncles and aunts "living in" to help out after a spouse had died. Southern blended families with Negro mammies produced a very different worldview than nuclear Yankee families, which are the default model in the U.S.
Very interesting. The book I mentioned reading up the thread about life expectancy also found that marriage in the Middge Ages was generally in the 20s or even late 20s for common people, because they couldn't afford their own setups until that age; whereas nobility often married in the teens. Because of wealth, they could afford the early marriages, which were considered more desirable. It was a very interesting book, I wish I had it with me now. It was a library book.