Born in
Philadelphia,
Pennsylvania, McGlynn saw action in the
United States Navy during
World War II, serving from 1943 to 1946. Returning from military duty, he attended
Mount St. Mary's College in
Emmitsburg,
Maryland, receiving a
Bachelor of Science degree in 1948 and a
Bachelor of Laws from the
University of Pennsylvania Law School in Philadelphia in 1951. He was an
Assistant United States Attorney in Philadelphia from 1953 to 1960. He worked in private practice in Philadelphia from 1960 to 1965. In 1962, he ran in a
special election as a
Republican to represent the 10th district on
Philadelphia City Council, but lost to
Robert B. Winkelman. McGlynn was a judge of the County Court of Philadelphia from 1965 to 1968 and a judge of the Court of Common Pleas for the First District of Pennsylvania from 1968 to 1974. ==Federal judicial service==