The Maryland state flag‘s alternating quadrants consist of imagery from the Coats of Arms of the Calvert and Crossland families. William Cooke has blogged extensively about Maryland flags and banners, including the Crossland banner.
The Maryland state flag is one of only four state flags that doesn’t contain the color blue. It’s also the only one based on English heraldry.
The two symbols were first put together in 1648 by the second Lord Baltimore, Cecilius Calvert.
Here’s what Wikipedia notes about historical usage of the Crossland banner:
The red and white colored arms of the Crossland family, which belonged to the family of Calvert’s (Lord Baltimore’s) paternal grandmother, gained popularity during the American Civil War, during which Maryland remained with the Union despite a large proportion of the citizenry’s support for the Confederacy, especially in the central City of Baltimore and the counties of the southern part of the state and the Eastern Shore of the Chesapeake Bay. Those Marylanders who supported the Confederacy, many of whom fought in the Army of Northern Virginia of General Robert E. Lee, adopted the Crossland banner, which was red and white with the bottony (trefoil) cross (seen as “secession colors”) and often used a metal bottony cross pinned to their gray uniforms or caps (kepis). The black and gold (yellow) colors with the chevron design of the Calvert familywere used in the flags and devices and uniform pins of the Union Army regiments in the northern Army of the Potomac.
After the war, Marylanders who had fought on either side of the conflict returned to their state in need of reconciliation. The present design, which incorporates both of the coats of arms used by George Calvert, began appearing.
The current state flag with both the Crossland and Calvert heraldry include was first flown publicly in 1880 at a parade honoring the sesquicentennial of Baltimore. It was also flown in 1888 at ceremonies marking the erection of monuments at Gettysburg honoring the Union regiments from Maryland who fought there. The new state flag was officially adopted in 1904.
More on the Crossland banner
More from Cooke:
It is interesting to point out that the Crossland Banner has not attracted the negative attention that other Confederate flags have. I believe that this is because the design was created centuries before the Civil War and should not even be considered a Confederate flag, on its own. Rather it was just one symbol that Confederates in Maryland adopted. Hate groups have not used the Crossland Banner, thankfully. Flying the Crossland is not seen as controversial as it has such a rich history and has a prominent place on our State flag. Indeed, ultra-liberal Howard County, uses the Crossland Banner on their county flag.