The pictured plants look like Leyland Cypress (cedars are different species and have a different appearance and pest/disease issues). Leyland Cypress are vulnerable to a couple fungal diseases that can kill branch tips or entire branches, with both diseases more likely to cause infections and greater damage on plants stressed by drought. (Maryland has been in a drought for much of the past two years, and if the Leylands haven't been periodically watered, that might be a contributing factor in their decline.)

You can learn more on the linked disease page, but essentially the only recourse is to prune out dieback and irrigate drought-stressed Leylands (when feasible) to reduce the stress on the plants to discourage worsening dieback. Old wood on evergreens like Leylands that has lost its foliage due to natural aging or to infections or pest outbreaks cannot grow it back, so expansive areas of dieback or bare stems will unfortunately remain bare even if the tree stops declining.

Miri