? When did they let the everybody have back packs ?

We always had to carry ours in our hand.

I used an early incarnation of this bag for decades.

https://www.amazon.com/Military-Tactical-Monoki-Backpacks-Traveling/dp/B07R5S6KSB?ref_=s9_apbd_orecs_hd_bw_b3W3emh&pf_rd_r=M2W5TBJ7VH03M0X97Q7M&pf_rd_p=fb0cf833-3a91-5643-b12b-72ec4d89a4fb&pf_rd_s=merchandised-search-10&pf_rd_t=BROWSE&pf_rd_i=3222113011