The first US military night vision system used in active combat was the T3 Carbine system – an infrared light-amplifying scope and IR floodlight mounted on an M1 Carbine. About 150 of these were used on Okinawa, and were quite effective. The system was refined over time, and by the Korean War this version was in service – an improved M3 scope on an M1 Carbine.
The M3 scope here has a longer effective range (125 yards), and still required the user to carry a heavy backpack-mounted battery pack to power the scope and light. They were used primarily in static defensive positions in Korea to locate troops attempting to infiltrate in darkness. In total, about 20,000 sets were made before they became obsolete, and were surplussed to the public.