Following graduation, Beecher worked as personal assistant to the highly influential James Hall for 10 years, and then at the request of Othniel Charles Marsh moved to New Haven to oversee the Yale Peabody Museum's growing collection of invertebrate fossils.
Following graduation, Beecher worked for 10 years as personal assistant to the highly influential James Hall who counted Fielding Meek, Charles Walcott and Josiah Whitney among his assistants. At the request of Othniel Charles Marsh Beecher moved to New Haven to oversee the Yale Peabody Museum's growing collection of invertebrate fossils.