First photo:
Although most of your other cartridges & casings are civil war era, this one, being "necked" and centerfire, is from no earlier than 10 years after the civil war ended in 1865. You do not mention it having a "headstamp" marking on its flat base, so I assume it is blank. Being a necked and unmarked centerfire, dug in America, indicates it is from the 1880s. I cannot find an exact match for one with the size-measurements you listed. It closely resembles a poswar .577 Snider-Enfield casing, but your measurements do not match up with .577-caliber.
Second photo:
The large ones are civil war era .52 Spencer Rifle/Carbine cartridges & bullets. The small one, which you say is .297" in diameter, is not in any of the civil war bullet books, so I suspect it is a slightly postwar rimfire cartridge.
Third photo:
It is a fired .44 Henry Rifle casing, manufactured during the civil war era and a few years after. As Fyrfytr1 mentioned, the Henry Rifle had a "double" firing-pin, with two flanges spaced 180-degreees apart. The fact that there are six strike-marks on your fired casing's base mean that the first and second times it was loaded and the trigger got pulled, it was a misfire. The shooter unloaded it and repositioned it in the Henry's chamber, giving it a second and third chance. On the third try, it worked.