The author follows hundreds of Welsh pioneers into Pennsylvania via the records of the various land companies who re-settled William Penn's famous grant of land along the Schuylkill River. For sources, he utilizes lists of settlers, land patents, plat maps, and biographical sketches to flesh out the process of settlement in Merion and the adjacent towns of Haverford and Radnor.
Still other important features are a study of the sometimes strained affairs between Welsh Tract settlers and William Penn, various personal accounts by the settlers, and a history of the Quaker meetings founded within the Welsh Tract.