Here is one of the first M1 Abrams in 1979. The Abrams entered service in 1980, but didn't see heavy combat until Desert Storm in 1991.
The Abrams was the first tank to incorporate British-developed Chobham composite armor, which includes ceramics and is incredibly dense.
Despite the British-designed armor, the Abrams tanks were made in Ohio and Michigan.
Source: GlobalSecurity.org
The Abrams is highly mobile, with a top speed of more than 40 mph and an impressive zero-turn radius.
Like with any armored unit, their success depends partly on the hardware and partly on the crew. Here, a loader expertly queues up a round capable of melting through an enemy tank's armor.
In addition to the main cannon, the Abrams sports a M2H Browning .50-caliber machine gun, a staple of the US military since World War II. In some cases, the guns can be remotely fired.
The M1 Abrams is just plain tough. Watch it roll over a car bomb without even closing the hatch. This would tear a lesser tank to shreds.
The US as well as Iraq, Saudi Arabia, Egypt, and Australia use the Abrams as their main battle tank.
When the Abrams finally saw combat in 1991, it impressed operators with it's effective rounds and virtual invulnerability to Iraqi tank fire. No Abrams was destroyed by Iraqi tank fire during the Persian Gulf War.
Source: US General Accounting Office
In fact, the only Abramses lost during the Persian Gulf War were destroyed by friendly fire, sometimes on purpose so they couldn't be reclaimed by Iraqi forces.
The Abrams benefited from having superior range and night-vision abilities compared to their Soviet-made counterparts.
During the 2003 invasion of Iraq, the Abrams became involved in urban warfare while clearing cities. Urban warfare is the worst situation for tanks, as their range is limited by buildings and they can be attacked from above, where their armor is weakest.
Source: USA Today
In response, the US outfitted the Abrams with the Tank Urban Survival Kit, which greatly improved survivability in urban areas.
Source: USA Today