Originally, the Ctrl key was to the left of A, where Caps Lock is now. This makes most Ctrl key shortcuts a lot more comfortable. They moved Ctrl to the bottom

Originally, the Ctrl key was to the left of A, where Caps Lock is now. This makes most Ctrl key shortcuts a lot more comfortable. They moved Ctrl to the bottom left with the Model M keyboard, which became the standard modern PC keyboard layout. As far as I can tell, the justification for this was that it made the layout more familiar to typewriter users, since Caps Lock is in the same position it's in on a typewriter (see https://bitsavers.org/pdf/ibm/pc/IBM_Personal_Computer_Seminar_Proceedings/PC_Seminar_V04_N02_198604.pdf https://bitsavers.org/pdf/ibm/pc/IBM_Personal_Computer_Semin... page 24). Personally, I always remap my key layout on every PC I use so left Ctrl is swapped with Caps Lock.