This company, located in Chester, PA a few miles south of Philadelphia, was developed by Sun Oil Company and launched its first ship in 1917 as the US was entering WWI. At the start of WWII it was among the country’s five largest ship yards and had eight slipways. Twenty slipways were added during the war making it the county’s largest shipyard. At its peak more than 40,000 workers were employed. The company built 281 T2 tankers during WWII, about 40% of the US wartime total. It also produced hospital ships, cargo ships and others. The majority offered in this group would be tankers. Each button is 1.5” with metal back and vertical pin. The dates on these range between Jan. 31, 1944 and July 26, 1944. All are NM to Mint.