A delegation of friends and well-wishers from the Bethlehem-Easton area of Pennsylvania crowded the House galleries today to witness the swearing in of their new congressman, Democrat Fred Rooney of Bethlehem.

Rooney, elected last week by some 6,000 votes over Republican Robert Bartlett, was sworn in under unusual circumstances. His certificate of election had not been filed with the House clerk, but Rep. Thomas Morgan, dean of the Pennsylvania Democrats in the House, called for unanimous consent for Rooney to take his seat, saying there is no question he had been elected to the unexpired term of the late Congressman Francis E. Walter.