The oldest Upjohn product still being made by Pfizer in 2020 is Gelfoam. The medical needs of World War II drove the development of it. The first product release was in 1945 and by 1950 there were 10 different Gelfoam products offered as shown below in the extract from a 1950 product listing. The example of a Gelfoam Size 12 product below has labeling typical to the late 1940s and 1950s. On the label there is a stock number of 1-609-500. That tells us that this batch of product was for a government contract, probably for use in military hospitals. The third photo below shows the making of a Gelfoam Santa in 1954. Gelfoam has been made in the same location in Building 41 for the last 70 years.