A sermon preached on the day of the Continental Fast at Tredyffryn, in Chester County, by the Rev. David Jones, A.M., Philadelphia, July 20, 1775.

When the Continental Congress called for a day of prayer and fasting on July 20, 1775, the Rev. David Jones was invited to preach to a gathering of the troops. In Crosswicks, New Jersey, his support of the cause of American Independence had aroused a great deal of opposition from loyalists. More than 3,000 men gathered at the church, along with members of the congregation and other spectators. The Pennsylvania Gazette of August 16, 1775, announced the publication of his sermon, "Defensive War in a Just Cause Sinless," and its availability at nine pence from booksellers in Philadelphia, Lancaster, and Burlington. In 1776, David Jones offered his services as a chaplain to the army and was assigned to the Fourth Pennsylvania Battalion under Anthony Wayne.