• Year First Flown: 1904
• Designed By: Based on the banner of Sir George Calvert of England
• Design: A flag divided into four equal quarters. The top left and bottom right are the same black and gold design that represents the English Calvert family. The top right and bottom left are the red and white arms that represents the English Crosslands family.
• Meaning: George was the first Lord of Baltimore and was given the black and gold coat of arms, which incorporated the colors of his father's family. The red and white arms belonged to the Crosslands family, George Calvert's maternal family, in 1622. The Calverts founded Maryland as a British colony in 1632, and the state was named after Queen Henrietta Maria.

The Maryland state flag was officially adopted on March 9th, 1904 and was (and still is) the only U.S. state flat to be completely based on heraldic emblems. The flag's design is based on the coat of arms of the Calvert family, who were the original colonial proprietors of Maryland. A similar flag was originally flown throughout the colonial period before the revolution, but after the American Revolution was discontinued. In 1854 a law was passed by Maryland Legislature in order to create a state seal that was based on the Calvert family colors and design. All of a sudden, gold and black banners and flags started popping up across the state. These "Maryland colors", as they were often referred to as, weren't officially adopted by the state but became a very popular symbol of the state of Maryland. At the start of the Civil War, Maryland was torn between its allegiance to the Union and its sympathies towards the southern states. Maryland remained in the union, but those citizens that sympathized with southerners began to use the red and white Crossland colors as a sign of resistance to the Union and known as the "Maryland secession colors". After the Civil War ended, a new symbol of the yellow/gold and red/white colors combined became popular. What had once been a sign of a division among Maryland had now been put together to symbolize the reunion of all of Maryland's citizens. The design that is now the official flag of Maryland became a popular flag and was flown throughout the end of the 19th century as an unofficial flag of Maryland until it was finally officially adopted in 1904.