The introduction of vaccines to the United States helped-

keep us healthy, I mean, I know I'm not gonna die over a small disease even though some of my ancestors wouldve.

Explanation:

get your vaccines, save yo self

the  seven  days  battles  were  a series of seven battles over seven  days from june 25 to july 1, 1862, near richmond, virginia,  during  the american civil war. the  seven  days ended with mcclellan's army in relative safety next to the james river, having suffered almost 16,000 casualtiesduring  the retreat.