The V.90 (56k) standard came out in 1998. Depending on what ISP you used they may or may not have had V.90 compatible equipment until later.
Before that there were two competing proprietary 56k standards (K56flex and X2) that existed, but if you bought one of the modems you had to make sure your ISP supported the modem you had to get the full benefit. I have a vague recollection that there was some reluctance among ISPs to pick a standard.
The V.90 (56k) standard came out in 1998. Depending on what ISP you used they may or may not have had V.90 compatible equipment until later.
Before that there were two competing proprietary 56k standards (K56flex and X2) that existed, but if you bought one of the modems you had to make sure your ISP supported the modem you had to get the full benefit. I have a vague recollection that there was some reluctance among ISPs to pick a standard.