"The M-1916 bacon can was a tinned iron can that held uncooked reserve meat rations. The lid of the bacon can was secured by friction and the can was stored upright in the haversack to prevent grease from spilling onto the rest of the gear. When the bacon can was empty, it had enough space to hold the M-1910 condiment can, thus saving space in the haversack."
Source: Pritzker Military Museum