Unlike other lawyers, Amasa Copp Paul chose his specialty while still in law school: patent and trademark law. While attending law school in Washington, D.C., he served as an Assistant Examiner in the U. S. Patent Office; after graduation he remained at the Patent Office "perfecting himself" for future practice. In May 1884 he moved to Minneapolis and associated with several lawyers until finally settling in with his brother Richard as Paul & Paul.
He became a titan in his chosen field. Although he was a member of several social organizations, the practice of law dominated his life. He found service on committees for the American Bar Association lobbying for salary increases for federal judges and for the separation of the Eighth Circuit from the newly formed Tenth Circuit very rewarding.
He died on November 13, 1936, at age 79. In memorial services for the Hennepin County Bar Association the following year, Charles R. Fowler recalled him:
"The engrossing pursuit of life to Mr. Paul, however, was the practice of his profession. Having acquired the education and experience which fitted him to practice, he enthusiastically and seriously entered upon his life work. He made a reputation as a patent lawyer second to none in the United States. He was a specialist in the law of trademarks as well as patent and was the author of 'Paul on Trademarks' in 1903, which was and is a standard textbook on that subject and has been and still is repeatedly cited by the Federal Courts."
The text of Amasa Paul's "The Law of Trade-Marks" is posted separately on this website.