did I bricked the Galileo board when I lost power while on USB
Yes, that might be the case, though in this case it's not totally bricked (at least these several cases reported so far for similar circumstances were able to recover), you may be able to restore that using DediProg. The best way to diagnose that is to take a look at the serial console using the 3.5 mm to serial cable - it will show you what's happening there. I assume you've tried the usual magic of rebooting your PC and power cycling Galileo, right?
An indirect way to check would be to use the SD card linux image, ensure that your home network has a DHCP server, which is setup to give out IP to the Galileo board, plug the ethernet cable into Galileo, plug in the power supply and check if the DHCP server has given out the IP, then try to SSH there. If the board boots, it will get the IP and you should be able to connect via SSH.