The Spring Azure (Celastrina ladon) is part of a family of small gray butterfly with a very similar appearance and a range throughout North America.
Range maps I have seen on the Azures have them up to Alaska, across much of Canada and only lacking in parts of Texas and Florida; and you will deifnitely find Azures in Maryland.
The tops of an Azure’s wings may be blue or have copper highlights depending on the species, but you will very rarely see those colors, and even in flight, the Azures are so small, its tough to make out any wing pattern. The arrangements of dark markings on the closed wings can help differentiate between the Spring, Summer, Echo, Holly, Lucia or whatever otehr Azure you wanna talk about.
They are very similar in appearance to Blues, but your dead giveaway is no orange marking and no tail extension on the hind wing.
Azures will walk across the ground with their wings closed. They will land on rocks, grass or dirt and spend time by puddles. I caught one shortly after a storm, once, so they are not scared of coming out soon after the rain.