*Key West Cemetery was founded in 1847 following a hurricane the previous year that destroyed the earlier cemetery located near present day Higgs Beach. To protect from future flooding, the 19-acre cemetery was located here on Solares Hill, the highest natural elevation in Key West. An estimated 75,000 people are interred here, divided among parcels that reflect the cultural diversity that continues to characterize the city of Key West today. The cemetery contains an historic Catholic section, Jewish section, the USS Maine Plot dedicated in 1900, and the Los Martires de Cuba, a memorial for those who fought in the 1868 Cuban revolution. In addition to these defined areas, African Americans, Cubans and Americans, rich and poor, are interred throughout. In-ground and crypt style graves range from simple concrete coffins filled with soil to elaborate monuments. Plot enclosures of wrought iron, wood, or concrete were often used to mark family plots.
*The above paragraph is what is written at the entrance marker when you go into the cemetery.
According to Wikipedia and current statistics it is estimated that as many as 100,000 people are buried there, many more than the 30,000 residents who currently live on the island.