Thompson was a younger cousin of Samuel Whitaker Pennypacker (1843-1916), historian, judge, and governor of Pennsylvania, and studied law with him.
[2] Thompson was nominated by President William Howard Taft on June 5, 1912, to a seat on the United States District Court for the Eastern District of Pennsylvania vacated by Judge John Bayard McPherson.
He was confirmed by the United States Senate on June 16, 1912, and received his commission on July 16, 1912.
His service terminated on February 3, 1931, due to his elevation to the Third Circuit.
[2] Thompson was nominated by President Herbert Hoover on December 4, 1930, to the United States Court of Appeals for the Third Circuit, to a new seat authorized by 46 Stat.