This is the Grand Union or Continental Colors. This was an official flag of the Continental Army. It was used as both a Naval Ensign and a garrison flag at the beginning of the Revolutionary War.
It was created by taking British White Ensign and simply painting red stripes on them. While other flags like the Gadsden, are more popular today, this was probably the most widely used flag by the Continental Army because they were easy to make. They simply re-appropriated British White Ensign flags that already existed.
The flag is 3'x5' and made from a premium 100 denier polyester. It has a white header with two grommets. There are four rows of stitches on the fly and two rows on the top, bottom, and header side. The image is screen printed and appears on both sides. Writing will be reversed on the back.
3'x5' flags are 3 feet x 5 feet, 36 inches by 60 inches, 91 cm by 152 cm, 1 yard by 1.7 yards. This is the most common size flag you see hanging on porches, small flag poles, hanging at festivals, and inside of bars and restaurants.