Charles Perry Sinnickson was born in Philadelphia on October 18, 1844, the son of Charles Sinnickson and Caroline E. Perry.
Sinnickson entered the University of Pennsylvania as a partial student in 1861, with the freshmen members of the Class of 1865. He joined the Zelosophic Society before leaving the University in June of 1862.
Sinnickson remained in Philadelphia, where he became a merchant. In 1900, he listed his occupation as lawyer.
In 1869 Charles Perry Sinnickson married Emma Sophia Rosengarten, daughter of George D. Rosengarten. They had six children: Caroline Perry, Elizabeth Rosengarten, Charles, George Rosengarten, DeWitt Clinton, and Fanny Rosengarten. The family home was located at 230 South 19th Street, on Rittenhouse Square. The 1900 and 1910 censuses show that Charles Sinnickson and his wife had five female servants, four of Irish background plus a French maid; their five living children were all at home in 1900, but by 1910 only two unmarried daughters were still living with their parents.