Capsmith sent me a Private Message, asking me to identify the cartridge-casings.
The one on the left, having a round-bottomed base with a pinhole in the center, is definitely a civil-war-through 1870s yankee .50-caliber Gallager Carbine bullet-casing.
The middle two casings SEEM to show a section of indented line a little bit above the casing's base-rim, which means they are "Benet-primer" casings, and that means they are 1868-through-1882. Those two casings look too damaged to get an accurate measurement of their diameter... so I can only roughly estimate their caliber, as .50 or perhaps a little larger. Being about the same length as the Gallager casing, I think they are .50-70 Springfield Rifle bullet-casings. To see some examples of Benet-primer .50-70 cartridges (and info about them), go to the following webpage and scroll about halfway down the page. Note, the indented line does not COMPLETELY encircle the casing. If that's not what I'm seeing on your two casing, let me know.
THE CARTRIDGE COLLECTOR
The casing on the far right in your photo also seems to be too damaged for an accurate diameter-measurement. My estimation is that it looks to be .50"-diameter or a little larger. Based on that, and being much shorter than your other three casings, I think it is probably a .52-caliber Spencer casing, That type also dates from the civil war through the 1870s or a bit later. The civil war ones didn't have the Benet-primer indentions on the casing's side.
Here's a photo of a Benet-primed (1868-1882) casing for the postwar .58 Alin-conversion Springfield Rifle.