I’m writing a story taking place in 1997. Was cough syrup containing codeine available without a prescription back then?
Does this wiki cite help?
*n the United States, codeine is regulated by the Controlled Substances Act. It is a Schedule II controlled substance for pain-relief products containing codeine alone or more than 90 mg per dosage unit. In combination with aspirin or acetaminophen (paracetamol/Tylenol) it is listed as Schedule III or V, depending on formula. Preparations for cough or diarrhea containing small amounts of codeine in combination with two or more other active ingredients are Schedule V in the US, and may be dispensed in amounts up to 4 fl. oz. per 48 hours without a prescription. Schedule V specifically consigns the product to state and local regulation beyond certain required record-keeping requirements (a dispensary log must be maintained for two years in a ledger from which pages cannot easily be removed and/or are pre-numbered and the pharmacist must ask for a picture ID such as a driving licence) and also which maintain controlled substances in the closed system at the root of the régime intended by the Controlled Substances Act of 1970 – e.g. the codeine in these products was a Schedule II substance when the company making the Schedule V product acquired it for mixing up the end product. In locales where dilute codeine preparations are non-prescription, anywhere from very few to perhaps a moderate percentage of pharmacists will sell these preparations without a prescription. However, many states have their own laws that do require a prescription for Schedule V drugs.
Codeine is also available outside the United States as an over-the-counter drug in liquid cough-relief formulations. Internationally, codeine is a Schedule II drug under the Single Convention on Narcotic Drugs.[4]*
I bought some in China last year. 
Still have it in the drug cabinet, in fact, if that helps your story any.
You can still buy it over the counter in limited quantities, depending on the state law. The Wal-Mart I work at doesn’t sell it, but two of the older “hometown” pharmacies in town do. I think they sell they generic Robitussin AC, but I’m not 100% sure since I’ve never bought it. I should though, just to take home and abuse. (Kidding (sort of, my APN can’t prescribe controlled drugs and this Rozerem isn’t cutting it))
OK, that last response works for me.
You can still buy codeine based cough syrups OTC in the U.S. under Federal Law. However, in some states it might be prescription only. In the only state I have information on, Georgia, It is legal to purchase one (1) 4-oz (118ml) bottle of the generic of Robitussin AC every 48 hours.
To purchase it, you first have to find a pharmacy that is willing to sell it to you, they need to log the purchase on a special controlled exemption log.
I work at a pharmacy, so the last time I had a bad cough, in January, I had the pharmacist order some for me.
Just head for Canada. From this site:
IIRC codeine cough syrups are prescription, though.
I’ve been getting codeine cought syrup by prescription, and hearing that it was a controlled substance with more restrictive limitations on filling and refilling and transferring prescriptions, since 1987, in Delaware and Maryland.