The history of the Pepsin Syrup Company dates back to the 1880s when Dr. William B. Caldwell first began prescribing his senna and pepsin laxative.

William Burr Caldwell was born March 27, 1839, in Shelbyville, Missouri, the son of Samuel B.F. and Lucinda Steele Caldwell.

In 1858 he attended the Eclectic Medical Institute in Cincinnati, Ohio. Soon after he became a student at a medical college in Keokuk, Iowa where he earned his diploma and began practicing medicine at Laclede, Missouri.

Shortly before the Civil War he moved to Bloomington, Missouri and began a drug store business. He was married to Miss Mary Spencer in 1864 and they them moved to DeWitt County, Illinois. Dr. Caldwell later attended Rush Medical College in Chicago, Illinois where he graduated in 1875.

Immediately after graduating, he moved to Cisco, Illinois to set up his medical practice. He remained in Cisco for 10 years, moving to Monticello in 1885 when he purchased the Hamilton and Company Drug Store on the southwest corner of the square. He sold the drug business just one year later to Charles G. Armstrong and Charles H. Ridgley and moved his medical practice upstairs.

Due to the popularity and high demand for his senna pepsin laxative, Dr. Caldwell began producing his prescription at the corner drug store by 1888.

It wasn't until 1892 that Dr. Caldwell's former store clerk, Charles H. Ridgley, conceived the idea of manufacturing the doctor's famous prescription. Dr. Caldwell gave Ridgely and his partner, John Bell, permission to go ahead and as a result "syrup pepsin" was made in small quantities, bottled, and sold in neighboring counties.

The following year John Bell sold his interests to local attorney, Harry Crea, and the Pepsin Syrup Company was formally organized for the manufacture and the sale of Dr. Caldwell's Syrup Pepsin with the company relocating to the law and abstract office of Mr. Crea.

The company progressed slowly until Harry Crea sold his stock to Allen F. Moore and Asler C. Thompson for $12, 500 in 1899. A year later, following newspaper advertising and distribution of free samples, sales of syrup pepsin had more than doubled and again the company was relocated, this time to the Lodge Building on the southwest corner of the square.

The company was growing so rapidly that by 1902, Syrup Pepsin Company needed larger facilities.

In August 1903, they purchased 180 feet of the William Holmes Block just west of the Wabash between Livingston and Washington Streets. This included the old Daniel Stickel residence on the hill, which seemed perfect, as it stood alone on a city block. With some remodeling and an extension added to the rear of the home, this two story brick home served as the factory for several years. It was at this time that Monticello residents began referring to this area as "Pepsin Hill."

Allen F. Moore who was beginning to push his credit to the limit began selling preferred stock and in 1906 finally convinced local druggist, John F. Hott, to join him in his venture.

Moore and Hott proved themselves quite well and a four story addition to the northeast corner of the building was made in 1914. Business continued to grow and in 1919 another addition was made. J.C. Llewellyn (husband of Piatt County Historian, Emma Piatt) drew the architectural plans and William F. Lodge was given the contract for the four story $100,000 building. This building expanded the manufacturing are and allowed space for shipping and storage.

Again expansion occurred in 1924 with the addition of two more buildings at the cost of $250,000. "The Welfare Building" was erected to house a cafeteria, women?s lounge, game room, medical facilities, men and women?s locker rooms and a large gymnasium with balcony. The "Administration Building" with the entrance on West Washington Street housed the offices as well as the main lobby.

In 1925, Pepsin Syrup Company was sold for a reported $5,000,000 to Household Products Company, a division of Sterling Drugs Products, owner of several medicine businesses including Bayer Asprin, Pape Dispepsin, Phillips Milk of Magnesia, and Danderine.

Production continued under Pepsin Syrup Company until 1934 when it was renamed Dr. W.B. Caldwell, Inc. followed by Dr. W.B. Caldwell Co., Division of Sterling Drugs, Inc. in 1943, Centaur-Caldwell Division (makers of Castoria, Campho-Phenique, Z.B.T. Baby Powder, and Molle Shaving Cream) in 1948, National Brands Division of Sterling Drugs, Inc. in 1956, and by 1965 commonly known as Glenbrook Laboratories.

In 1984, Sterling Drugs Inc. announced they had signed a contract selling all trademark rights and inventories to Mentholatum Company of New York who closed the Monticello Plant in October 4, 1985.