Considering how often most we hear of German wonder weapons I decided to start a thread on what if American wonder weapons got used earlier and with better effectiveness.

Directory of U.S. Military Rockets and Missiles - Appendix 1

My favorite speculation is the Aeronca GB-4.

"In July 1942, the USAAF's Wright Field Equipment Laboratory began the development of the GB-4 guided glide bomb under project MX-108 (later continued as MX-618). The 3.72 m (12.2 ft) long GB-4 was basically an AN-M66 900 kg (2000 lb) general-purpose bomb fitted with a 3.66 m (12 ft) wing and twin tails. Under its fuselage it carried an AN/AXT-2 TV camera and transmitter. The latter's image was displayed to the bombardier, who could then send radio commands to correct the glide bomb's course. The GB-4 flew at a speed of 385 km/h (240 mph) and the accuracy under optimal conditions was around 60 m (200 ft) CEP.The GB-4 was declared combat-ready in July 1944, and the first units were then used by a specially formed bomber group in Great Britain. However, the initial combat results were disappointing, not the least because of technical difficulties but also because the TV image was too fuzzy on anything other than a clear day. More than 1000 GB-4s were produced, but only relatively few were actually used in combat, even though the results somewhat improved over time. The USAAF also tested a pulsejet-powered derivative of the GB-4 as the JB-4, but the GB-4/JB-4 project was terminated at the end of World War II."
GB Series

Now lets say the researchers managed to fix the fuzzy image problem so its CEP is down to 100 feet and get it ready in 1943 in large numbers...