“Without a doubt the most historic location in Morrisville PA is the Summerseat building located near the corner of Legion and Hillcrest Avenues. Built in the 1760's about a half mile from the falls of the Delaware River, the house once was the centerpiece of an estate that covered 220 acres in Bucks County, Pennsylvania. Early records indicate that the house was constructed by Adam Hoops, a wealthy Philadelphia merchant and was used as his seat during the oppressive Philadelphia summers. Summerseat's claim to fame was established in 1776 while it was owned by Thomas Barclay, Adam Hoops's son-in-law. Barclay and the house overlooking the Delaware were hosts to George Washington and his forces from December 8th to the 14th, 1776, a crucial period in the struggle for national independence. Barclay later served as America's first consul overseas, negotiating the United States' first treaty with a foreign country--Morocco--in 1786, a treaty that is still in effect today Summerseat also served as a courthouse in 1781 when General Anthony (Mad Anthony) Wayne conducted a trial of two British spies.”277

“Summerseat's Thomas Barclay was Scots-Irish, born in Strabane, County Tyrone in Ulster in 1728. He came from a Protestant mercantile and propertied family in northern Ireland, whose forebears had emigrated from western Scotland's County Ayr during the Plantation of Ulster in the seventeenth century... Barclay’s father Robert was a merchant and ship owner in Londonderry and Strabane. He was descended from one of three Barclays who helped settle Ulster.”261