The earliest known Riley immigrants to the Chesapeake Bay Area were the three brothers - Garrett, Miles, and Thomas - arriving in Northern Virginia in 1635. Many of the oldest, surviving Riley Colonial Records and Land Grants of Maryland and Virginia, which are dated late 1600s and early 1700s, pertain to these immigrants and descendents. Many early Colonial Rileys used Christian names taken from the Bible, such as Samuel, Pharoah, Jeremiah, and Eliphaz. Moreover, early Rileys in Colonial America passed down many traditional given names used by O'Reillys (Anglicised as Reyley or Riley) in Ireland, such as Brian (Briain), Farrell (Ferghail), Hugh (Aodh), John (Seaán), and Miles (Maolmordha). And, in Colonial days, many Rileys of the Tidewater Frontier were related and moved in and out of the Colonies now known as Maryland and Virginia. In addition to three Rileys mentioned by name above, there were other Riley immigrants who came to Maryland and Virginia in the late 1600s and early 1700s. In this book, the writer discusses all known individuals of early generations of eight different Riley lines from the time of arrival of their immigrants to approximately 1850. By 1850, all of these Riley lines had multiplied so greatly that tracing their descendents to those living today is almost an impossible task. From 1850 to the present day, the writer discusses only his own branch of Rileys. Prior to this publication, such a comprehensive analysis of the early Riley families of Colonial Maryland and Virginia did not exist.