The Springfield Model 1868 was one of the rifles which used the trapdoor breechblock design developed by Erskine S. Allin.

This conversion consisted of replacing the percussion lock with the breech-loading trapdoor mechanism, and relining the barrels to convert them from .58 to .50 caliber.

This model served as the basis for the definitive Springfield Model 1873 series of rifles in .45-70-405 caliber, which was adopted in 1873 as the standard military longarm of the United States armed forces for the next 20 years.

This model is unique in the trapdoor series by being marked with the actual year of manufacture (1868, 1869, or 1870) on the breech-block.

The army wanted to standardize weapons and ammunition, and forced these units to switch to trapdoor Springfields once the Model 1868 went into full production.