Pennsylvania Statutes Title 53 P.S. Municipal and Quasi-Municipal Corporations § 451. Organization;  expenses

The cities of any one class in this Commonwealth and the cities of two or more classes uniting together for the same purpose may form and organize leagues of said cities and hold annual conventions for the study and consideration of such municipal affairs as concern and pertain to the cities comprising the league.  Each city member of a league shall have the right and power to send delegates thereto and to pay the necessary expenses incident to their attending said convention, and to pay dues to the league, and to provide a fund for the necessary costs and expenses of league and league conventions and the work carried on by said league.