Zekiah Swamp is part of the Potomac River basin in Charles County, Maryland in the United States. The swamp is of braided stream stretching the length of Charles County and is a tributary of the Potomac River. It sits at an elevation of and of its southern end is protected as the Zekiah Swamp Natural Environment Area. The Maryland Department of Natural Resources has the authority to purchase an additional for the park. Charles County has moved to protect an additional of the wetland. The headwaters of the swamp are protected as part of Cedarville State Forest. It was first accurately surveyed by John Henry Alexander, Maryland's official cartographer, in 1835, as "Allen's Fresh". History Maryland was formed as an English colony in 1634. One of the original Thirteen Colonies, the Province of Maryland was established by Cecilius Calvert, 2nd Baron Baltimore as a haven for Roman Catholic Englishmen. Much of Zekiah Swamp is now thickly wooded and very swampy, but during the colonial period it was a center of activity for the growing colony. A courthouse was built in 1674 and archaeologists believe they have found the location of a "summer house" constructed by colonial governor Charles Calvert, 3rd Baron Baltimore. Archaeologists have searched for a fort built in 1680 to resettle a group of "friendly" Piscataway Indians. The courthouse was built in 1674 at Moore's Lodge. It served as the Charles County courthouse until 1727 when the county government was moved to Port Tobacco. Early maps included a drawing of the courthouse. The drawing has allowed historians to know exactly what it looked like despite being unable to find its precise location for many years. Charles Calvert, son of Maryland's founding governor Cecil Calvert, built a home in the area in 1674. The home known as His Lordship's Favor as a summer home and as a retreat from his "political enemies" at the colonial mansion at Mattapany which is now part of Patuxent Naval Air Station. Calvert intended to build a brick home rather than the usual wooden structure built by colonists in the area. He had to settle for a wooden home, but did build a brick chimney. Archaeologists found what they believe to be the site of the home, but have not found any artifacts that can be dated back to the 1670s. It is speculated that Calvert never actually occupied the home. Charles Calvert was