From Alton, IL, they were most likely made by W-W, oops, excuse me, Olin Chemical. Time frame? I'd guesstimate late 60s - mid 70s. I'm sure others will be along w/more specific data.
It was probably East Alton, IL. Olin Corp. (Winchester) I lived within 6 blocks of there in the mid 60's. They moved the ammunition mfg to ? Louisiana a couple years ago due to the union demands. Area lost 1000 jobs.