AT&T's purchased Pacific Telesis in 1996.
Pacific Telesis was one of the "Baby Bell" regional companies that was formed after the breakup of the Bell System monopoly.
The deal gave AT&T expanded coverage in the West Coast, most notably the wireless infrastructure of PacTel Cellular.
It also helped build out AT&T's long distance, wireless and Internet services via PacTel's large subscriber base across California and Nevada.
In 1999 AT&T acquired Ameritech, which at the time was serving 12 million phone lines across five Midwestern states.
The $62 billion deal enhanced AT&T's national footprint.
The merger had some critics in the regulatory space, leading AT&T to agree to various divestitures and operating restrictions.
With Ameritech on board, AT&T now boasted a coast-to-coast network.
AT&T purchased Comcast Cellular for $1.7 billion.
The transaction gave AT&T a valuable subscribers in the nation's third largest wireless market in Philadelphia and surrounding areas.
It also put further pressure on Bell Atlantic and SBC.
AT&T's $54 billion purchase of cable television operator MediaOne in 2000 helped the company look beyond phone services to position itself better into broadband and pay TV.
The MediaOne deal firmly established AT&T as the nation's largest player in cable, adding millions more subscribers.
But the rapid expansion came at a steep cost, saddling AT&T with heavy debts.
AT&T's $4.4 billion acquisition of Southern New England Telephone (SNET) in 1998 continued the company's aggressive expansionist strategy as it assembled the pieces to rebuild itself into a national telecommunications powerhouse after the breakup of the Bell System.
The deal to absorb Connecticut's dominant local phone company boosted AT&T's presence in the lucrative Northeast corridor and added over 1 million valuable subscribers.
Coming a year after its blockbuster merger with Pacific Telesis, the SNET purchase represented another step towards AT&T's vision of delivering local, long distance, wireless and data services across the full range of U.S. markets—essentially reconstituting Ma Bell.
While posing concerns about reduced choice from some consumer groups, analysts saw the deal as vital for AT&T to bulk up and compete with its increasingly consolidated rivals in a rapidly changing technological landscape.
AT&T rocked the telecommunications world in 1999 with its $48 billion purchase of cable television giant TCI, announcing its intent to transform itself into a broad "one-stop shop" provider of phone, video, Internet and wireless services.
The blockbuster deal followed a furious bidding war with Comcast and immediately made AT&T the dominant player in the cable industry while accelerating the "convergence" of telecom, television and online content.
TCI's huge subscriber footprint, CE John Malone's programming assets, and AT&T CEO Michael Armstrong's vision of blended service bundles were seen as ideal complements.
But execution struggles followed, including sky-high upgrade costs pushing AT&T billions into debt.
While Armstrong's convergence mission proved ahead of its time, the immediate fallout of the audacious TCI deal would force AT&T into a wrenching restructuring and retreat from cable just a couple years later.
AT&T's $86 billion purchase of BellSouth in 2006 represented a watershed moment, effectively reuniting two of the core components of the former Ma Bell empire and realizing a decades-long quest to rebuild the nationwide scale and bundled service offerings that were lost after the breakup of the Bell System monopoly.
With BellSouth, AT&T absorbed another former "Baby Bell" regional company, adding tens of millions of local phone subscribers across high-growth southern states as well as full control of the increasingly critical wireless unit Cingular.
Regulators and consumer groups voiced concerns about impacts to competition.
But over a decade after the 1996 Telecom Act accelerated competition, the industry consensus saw consolidation as inevitable in maturing markets with surging demand for integrated mobile voice, video and data services.
For AT&T, bringing BellSouth back into the fold cemented its resurgence as the nation's communications leader.
AT&T's $2.8 billion buyout of Dobson Communications in 2007 continued the company's campaign to blanket the nation in wireless connectivity, bulking up its subscriber ranks in rural cellular markets.
While tiny compared with earlier megamergers like the acquisition of BellSouth, the deal was strategically significant by filling holes in coverage across 17 states.
It also reflected the relentless competitive pressures of the maturing U.S. mobile sector, which was rapidly consolidating into a handful of national players.
Smaller carriers like Dobson faced high costs keeping up with network technology upgrades, all but forcing them into the arms of one of the big players.
Soon after closing the Dobson purchase, AT&T unified all of its wireless branding under the AT&T banner.
AT&T's purchased the Wi-Fi hotspot provider Wayport for an undisclosed sum in 2008.
While tiny next to AT&T's multi-billion dollar mega-mergers, the deal carried outsized strategic importance for blending hotspot access with AT&T's cellular and wired connections.
This heralded a vision of future mobility centered on blanket connectivity across different standards and technologies—an expectation that has since become commonplace for tens of millions of Americans with smartphones, tablets and laptops.
The Wayport acquisition gave AT&T control over 20,000 hotspot locations to pair for its 3G/4G network.
AT&T's $944 million acquisition of Centennial Communications in 2008 helped them expand coverage into Louisiana and Mississippi.
While small next to earlier blockbuster deals for the likes of BellSouth, Centennial's roughly 450,000 mobile subscribers represented an attractive asset as competition intensified among national carriers and rural network operators faced high costs keeping pace.
For AT&T, folding in Centennial's assets in the Gulf Coast delivered greater economies of scale as well as the opportunity to market bundles with its wireline offerings in the region.
And the pickup fit firmly within Ma Bell's post break-up playbook of opportunistically acquiring regional providers market-by-market in order to stitch together a new nationwide footprint matching the dominance of the old Bell System empire.
With its $1.2 billion acquisition of Leap Wireless in 2013, AT&T snapped up the prepaid wireless provider Cricket to bolster Ma Bell's lineup of discount mobile offerings.
While dwarfed by AT&T's earlier huge buys like DirecTV and BellSouth, the deal carried significance by allowing the company to better compete with the fast-growing prepaid segments that appealed to more budget-conscious subscribers.
The fast-changing wireless business was requiring carriers to segment the market across premium and low-cost brands. Cricket's barebones monthly plans and no-frills approach aligned well with AT&T's desire for a fighter brand going toe-to-toe with rival prepaid offerings.
Letting Cricket maintain its own unique brand and culture while gaining AT&T's financial backing and network resources proved a winning combination over the remainder of the 2010s.
AT&T's $49 billion purchase of satellite broadcaster DirecTV in 2015 marked a pivotal move to reorient the colossal carrier toward media and entertainment.
Six years after AT&T's earlier effort to integrate networks and television through the disastrous takeover of TCI blew up and forced a retreat from cable, maestro Randall Stephenson scored a cord-cutting era sequel success by acquiring the nation's leading satellite TV provider with 20 million subscribers.
The vision was to resurrect the "one-stop shop" triple play of video, broadband and wireless baptized in the TCI deal, but with refined execution and the benefit of AT&T's vastly expanded fiber optic and 4G architectures.
Despite persistent concerns over cord-cutting trends, AT&T subsequently doubled down by pursuing the landmark $85 billion takeover of Time Warner as well three years afterward—setting the table for another era-defining transformation.
AT&T's blockbuster $85 billion acquisition of entertainment giant Time Warner in 2018 represented a bold bet to control both content and the pipelines to consumer eyeballs as the digital media ecosystem endured deepening tremors.
The deal united Time Warner's lucrative stable of movies, television and news properties like HBO, CNN and Warner Bros. with AT&T's wireless, broadband and satellite networks.
The vision was to fuel AT&T's online streaming ambitions to battle Netflix and Disney for the fast-transitioning home entertainment space.
But the deal faced years of opposition from the U.S. Justice Department on antitrust grounds before ultimately being allowed to proceed with no conditions.
The huge debt load has also forced AT&T to shed assets like DirecTV, while the wisdom of its media merger gambit remains subject to fierce debate.