Not to be confused with the professional basketball team from the same city, the New York Knickerbockers were New York City's first professional baseball team in the mid-19th century. One of the team's original members - Walter T. Avery - signed the top of this 4x6" ledger page with dollar values noted in a column on the right side. It appears that the writing is in Avery's own hand. Comes with PSA.