In the leisure he enjoyed his figure was often seen in Congress. He relished the debates which at the time were on the Treaty with England. He
declared he heard as good speaking there as in the House of Commons. He observed—
A Mr. Amos speaks as well as Mr. Burke; but in general the speakers are more argumentative, and less rhetorical. And whereas there are with you not more than ten or a dozen tolerable speakers, here every member is capable of speaking.
While none of the letters to Priestley's friends mention a family event of some importance the American Advertiser, February 13, 1796, announced that
Mr. William Priestley, second son of the celebrated Dr. Joseph Priestley, was married to the agreeable Miss Peggy Foulke, a young lady possessed with every quality to render the marriage state happy.
This occurred very probably just before the Doctor set forth from Northumberland to make his first Philadelphia visit. It is singular that little is said of the son William by the Doctor. Could it be that, in some way, he may have offended his parent? In his Memorial Rush, writing in the month of March, 1796, noted:
Saw Dr. Priestley often this month. Attended him in a severe pleurisy. He once in his sickness spoke of his second son, William, and wept very much.
Busy as he was in spreading his religious tenets, in fraternizing with congenial scientific friends, his thoughts would involuntarily turn back to England:
Here, though I am as happy as this country can make me ... I do not feel as I did in England.