Foreign currency exchange?

I just returned from a trip to Canada, and I need to exchange Canadian dollars for US. Apparently my credit union does not do international currency exchange, and even though google says western union does, the multiple locations I’ve contacted all say they do not. I need to exchange this money that I already have, since I was unable to do it before I left Canada. I do not have an account with any other local bank outside of the credit union. Does anyone have recommendations for where I can exchange my Canadian dollars for USD?