In truth, the origins of the F-15 program date back before the early 1970s. In the mid-1960s and through the Vietnam War, the United States Air Force relied heavily on jet fighters designed in the 1950s. Fighters like the North American F-100 Super Saber, the Republic F-105 Thunderchief, and the McDonnell-Douglas F-4 Phantom II.
Though all of there were supremely powerful, capable, and adaptable jets, they all fell victim more often than not to smaller, lighter, and more maneuverable Soviet jets. Fighters like the MiG-17, MiG-19, and the MiG-21 routinely gave U.S. Air Force, Navy, and Marine Corps pilots all the hell they could handle. Though some dogfights turned out favorably for American fighters, a fair amount did not.
The prospects of great swaths of American pilots floating down over enemy territory with their airplanes spiraling out of the sky on fire was one the Pentagon surely wanted to put behind them. Upon the conclusion of the Vietnam War, it was clear a new strategy was needed for American fighter jets.
The Eagle was rare among its contemporaries, as it completely skipped having a YF designation added to its name during early flight testing. It, along with the Grumman F-14 Tomcat, are two of the few American fighters with this distinction.
With two powerful Pratt & Whitney F100-PW-220 after-burning turbofans on offer in the upgraded F-15C Eagle, the jet could blitz past twice the speed of sound at high altitude and even maintain supersonic down at sea level. Combine this with a slew of AIM-7 Sparrow, AIM-9 Sidewinder, and AIM-120 AMRAAM air-to-air missiles at its disposal, and no wonder the Eagle racked up a record of over 100 enemy aircraft shot down without so much as a single loss.
Even with this being the case, that's an awe-inspiring service record. That's without even including the exploits of the multirole upgrade path for the Eagle, the F-15E Strike Eagle, which first flew in the late 1980s. Overall, the F-15 is one of the finest fighter planes ever to fly. That's why even as the F-22 Raptor and F-35 Lightning II continue to receive most of the media attention, militaries across the globe are still all too hesitant to give up their prized Eagles. That alone should speak volumes.