Other than the very first type of photograph, the Daguerreotype, the photographic image first was captured on a negative. The earliest negatives were glass plate. It wasn't until 1889 that the first flexible film or Nitrocellulose/Nitrate film was invented by Eastman Kodak in 1889.

Timeline of Negative Development:
Glass Negatives: 1851 - the 1920s
Lantern Slides: 1860s -- 1930s
Nitrocellulose Film: 1889 - 1939
Safety Film: 1934 - present
Polyester: 1965 to present
Digital: 1991 to present