Founded in 1869, AIA Philadelphia is among the oldest and most distinguished of AIA Chapters, with a long history of service to members and the public. AIA Philadelphia organizes architects in the region for the purpose of advancing their influence in shaping the built environment, and their ability to effectively practice architecture in an ever-changing society and competitive marketplace. The Chapter provides opportunities for professional development, service, and collegiality among peers. A Chapter of The American Institute of Architects, the association represents over 1,500 member architects within four southeastern Pennsylvania counties: Philadelphia, Chester, Delaware and Montgomery. Through its myriad programs and events, the Chapter attracts design professionals from Eastern Pennsylvania, Southern New Jersey and Delaware. The Chapter also represents more than 263 member architecture firms and 228 affiliate companies supplying products and services to the industry.