It seems to me that Maryland recognizes ebikes, they just call them mopeds. The Maryland vehicle law says specifically that mopeds are not motor vehicles, but bikes and that they are not subject to the regulations of motor vehicles, but the regulations of bicycles.

As far as I can tell the only differences between that federal definition of an ebike and the maryland definition of a moped are:
-Fed says 1HP limit, Maryland says 1.5HP limit.
-Fed is strictly electric motors less than 100 pounds. [Although I don't see why this should be a determining factor in terms of lawful operation. Doesn't a hummer obey the same laws as Prius?]
-Fed gives a 20mph cap. [A bit silly in light of the fact that even pedalcycles can occasionally edge past 20mph.]

In any case, I was just pointing out the fact that people have to be careful. Ebikes appear to be well recognized in Maryland, but there's that one rule about requiring a license that could get some people in trouble if they aren't aware of the fact that Maryland uses the term "moped" instead of "ebike". Other than that you can treat an ebike in Maryland just as you would any other bike (except for sidewalk riding, but many states don't allow bikes on sidewalks anyway).