American Eagle is an American brand name for the regional branch of American Airlines, under which nine individual regional airlines operate short and medium haul feeder flights. Three of these airlines, Envoy Air (formerly American Eagle Airlines), Piedmont Airlines and PSA Airlines, are wholly owned subsidiaries of American Airlines Group. Mainline carriers often use regional airlines to operate services in order to increase frequency, serve routes that would not sustain larger aircraft, or for other competitive reasons. They primarily connect smaller cities with American's domestic hub airports, although they do offer some point-to-point service between non-hub airports. Just like the regional brands of the other two major airlines (Delta Connection, and United Express), American Airlines' regional brand accounts for more than 60% of American Airlines flights.

The E170/E175 models in the 80-seat range are the smaller in the EJet family. They are powered with General Electric CF34-8E engines of 14,200 pounds (62.28 kN) thrust each. The E170 and E175 directly compete with the Bombardier CRJ-700 and Bombardier CRJ-900, respectively, and loosely compete with the turboprop Bombardier Q400. They also seek to replace the market segment occupied by earlier competing designs such as the BAe 146 and Fokker 70.

The Embraer 170 was the first version produced. The prototype 170-001, registration PP-XJE, was rolled out on 29 October 2001, with first flight 119 days later on 19 February 2002. The aircraft was displayed to the public in May 2002 at the Regional Airline Association convention. After a positive response from the airline community, Embraer launched the E175. First flight of the stretched E175 was on June 2003. The launch U.S. customer for the E170 was US Airways, after FAA certification, the aircraft entered into revenue service on April 4, 2004 operated by the MidAtlantic division of US Airways, Inc. The first E175 was delivered to Air Canada and entered service in July 2005. The 170-001 prototype performed its last flight on April 11, 2012. Its destiny was disassembly in the US for spare parts.