In 1924, when state highways were first publicly signed, most of what is now NY 7 between Binghamton and the Vermont state line was designated as New York State Route 9, continuing the numbering of New England Route 9 in Vermont. Within Albany, NY 9 followed the modern routing of NY 2 through Latham to Troy, where the connection to the modern alignment of NY 7 was made via current US 4. In 1927, NY 9 was redesignated as NY 7 to avoid conflict with US 9. The route north of Binghamton remained unchanged in the 1930 renumbering; however, south of Binghamton, NY 7 was extended to the Pennsylvania state line, where it became PA 29.