Counties in Maryland

• Allegany (43 historic properties)
• Anne Arundel (103 historic properties)
• Baltimore (366 historic properties)
• Calvert (20 historic properties)
• Caroline (20 historic properties)
• Carroll (60 historic properties)
• Cecil (50 historic properties)
• Charles (37 historic properties)
• Dorchester (24 historic properties)
• Frederick (91 historic properties)
• Garrett (19 historic properties)
• Harford (78 historic properties)

• Howard (34 historic properties)
• Kent (40 historic properties)
• Montgomery (71 historic properties)
• Prince George's (90 historic properties)
• Queen Anne's (37 historic properties)
• Somerset (73 historic properties)
• St. Mary's (31 historic properties)
• Talbot (63 historic properties)
• Washington (95 historic properties)
• Wicomico (22 historic properties)
• Worcester (32 historic properties)