The Maryland State Archives is gradually introducing new online records. And on 6/22/2002, the Archives announced that partial scans of the male and female marriage indexes for Cecil County are available online. The male index covers 1928-1977, while the female index is 1928-1935. Access is free.
For Dorchester, the Archives added the Dorchester County marriage records for 1865-1886
Here’s the link for the Dorchester County Marriage Records.