Thomas Jefferson was VERY important because not only did he write the Declaration of Independence, but when he was President (he was the third) he made the Louisiana Purchase, which is when he bought all the land West of the colonies. If it wasn't for him we wouldn't have 2/3 of what the US is today! Thomas was born on April 13, 1743 in Albemarle County, Virginia, and he was the son of Peter Jefferson. Peter was a planter, and surveyor. and Thomas's mother, Jane Randolph, was the daughter of Isham Randolph, and Isham was a ship's captain and a planter. Thomas had a tutor who privately taught him at home and at school. He then went to the College of William & Mary in Williamsburg. Thomas was a circuit lawyer and was admitted to the Virginia bar in 1767. He married Martha Wayles Skelton Jefferson in 1772. Jefferson was elected a deputy to the Continental Congress in 1775 and in 1776. The Declaration of Independence was signed on July 4, by the representatives of the 13 Colonies of America, which is why we celebrate July 4, also known as "Independence Day".