He is known for his role in establishing the American Pharmacists Association, his work on the United States Pharmacopeia, and was the author and editor of the first pharmacy textbook published in America.

Isaac died in 1831 and William, at 14 years old, moved to Philadelphia, Pennsylvania, U.S., to start an apprenticeship.

Elias Durand, a nearby pharmacist trained in France, encouraged Procter to pursue investigations.

[6] Rather than a soda fountain,[citation needed] his shop included a laboratory and a writing area where he wrote scientific papers, practical articles, and editorials.

He investigated a series of volatile oils, where he experimented with new methods and apparatus, and his results were published in the American Journal of Pharmacy.

Wholesalers paid for analysis before accepting a shipment, and the imported drug materials could vary widely in quality.

In response, the Pharmacopeia of the United States was created to establish standards for drug quality, the first edition being published in 1820.

Trimming costs by reducing the number of pages and financial assistance from the college helped it survive.

His lectures covered pharmacy techniques such as maceration, percolation, and distillation followed by a discussion of drugs and preparations.

That changed in 1847 with the arrival of one from Germany: Lehrbuch der pharmaceutischen Technik by Karl Friedrich Mohr.