The U S has made the zinc cent since 1982. I metal detect a lot and some zincolns (zinc Lincoln cents) I find in the ground are eaten away, sometime half eaten away being only 7 to 10 yrs old. I've found 145+ yr old Indian Head cents (in the ground) that are 95% copper and come out of the ground sometimes in VG to XF condition. I think in the near future, the U S will go to the copper plated steel cent as Canada has had since 1999, although Canada did overlap alloys - copper plated zinc, from 1999 to 2012, which was the final minting of the Canadian cent.