1. Year and State and more.
Students oftentimes forget the commas after 1776 and Massachusettes. You are repeating the time and location, respectively, just as if you were saying "John, who likes football, also likes baseball." The year and "Massachusettes"below and the who statement above are all like additional notes in a way and you need a comma on both sides.
I was born on July 4th, 1776, in Boston, Massachusettes, on a rainy day.