The Philadelphia 76ers name originates from the year 1776, the year the Declaration of Independence was signed in Philadelphia.
The team's traditional red, white and blue color scheme is used to help drive home the point, along with the 13 stars that are arranged in a circle above the "7" in certain variations of the logo, as both originated from the original United States flag that was made by Betsy Ross in Philadelphia.
The franchise was originally the Syracuse Nationals, but switched the name to the 76ers when it moved to Philadelphia for the 1963-64 season.
The team is commonly referred to as the Sixers for short, making it a bit easier to either forgot or not think about the origin of the full nickname.
There has been a much bigger push recently by the franchise to call back to the roots of its name, such as naming the mascot Franklin in honor of Philadelphian and Founding Father Ben Franklin, ringing a ceremonial Liberty Bell before each home game and the team's playoff logo for the 2018 postseason, which took imagery from one of Ben Franklin's political cartoons about division among the colonies and why they needed to unite to gain freedom.