>>82856489
>>82857655
The Twin Mustang got started during the war as a way to say "well, we have Mustangs, and they're good, but we need them to be longer ranged for bomber escort..." and so North American just said "Lets bolt two of them together!" But that kinda fell by the wayside a bit because regular Mustangs got drop tanks and better range in general, P-38s were already around, and P-61s showed up to handle long-range night-fighter stuff, especially in the pacific.
Then they revived it a few years after the war because "Oh shit, the Soviets are building bombers just like we did", and we needed to do things like fly patrols over Alaska, which P-80s and the like most definitely didn't have the range for. And then we needed planes for Korea, too, so this silly conjoined twin soldiered on until the airframes wore out in the mid-50s.
Fun Fact: The last time the Mustang (the regular one, not the twin one) saw combat was in the Soccer War between Honduras and El Salvador in July 1969, over 20 years after WWII. Ironically, against the F4U Corsair.