American Tower is an American real estate investment trust and an owner and operator of wireless and broadcast communications infrastructure in several countries worldwide and is headquartered in Boston, Massachusetts.
It is ranked 410th on the Fortune 500.
As of December 31, 2018, the company owned 170,686 communications sites, including 40,757 sites in the U.S., 75,872 sites in Asia, 16,665 sites in Europe, Middle East and Africa, and 37,392 sites in Latin America.
The company was formed in 1995 as a unit of American Radio Systems. In 1998, American Radio Systems merged with CBS Corporation and completed the corporate spin-off of American Tower. Following the merger, American Tower began international expansion by establishing operations in Mexico in 1998 and Brazil in 1999. The company began purchasing numerous AT&T Long Lines microwave telephone relay towers. Upon acquisition of these sites from the now defunct AT&T Communications, Inc., American Tower began repurposing the towers for use as cell towers, and leasing antenna space to various American cell phone providers and private industries. Then, most of the former AT&T Long Lines sites had their horn antennas removed, either by helicopter or by crane, to make room for more antennas. Since AT&T's Long Lines Program was decommissioned in the 1980s, and the company no longer had any use for the towers themselves, American Tower now owns most of these tower structures across the entire continental United States.
In 2005, American Tower acquired SpectraSite Communications, expanding its global portfolio to over 22,000 owned communications sites including over 21,000 wireless towers, 400 broadcast towers and 100 in-building DAS (Distributed Antenna System) sites. The merger further established American Tower's position as one of the largest tower owner and operators in North America.
Between 2007 and 2012, the company expanded internationally with operations in India, Peru, Chile, Colombia, South Africa, Ghana and Uganda.
In 2013, the company acquired Global Tower Partners for $4.8 billion. This acquisition added sites to the U.S. portfolio and added operations in Costa Rica and Panama.