A pair of antique brass military buttons, by Horstmann Brothers & Co. of Philadelphia. I am no military button expert and have researched these as much as possible, to my ability. I'm presenting them based on what I have and have not found, information-wise and hope the photos show enough information to complete the description.
They are 3/4" wide, each with a heavy soldered wire loop shank.
What I believe these to be are US Army buttons from the Indian Wars period (1875-1902). They are marked "Horstmann Pros. & Co. Phil." with a dot before and after the 'Phil'. The mark with 'Phil.' (and not Phila/PhiladA/Philadelphia) was used between 1880 and 1902.
The 'Brothers' part of the backmark is a bit of a mystery, as it is spelled 'Pros' and not 'Bros'. Initially, I thought the 'B' was partially worn, but it is in fact a capital 'P'. It may well be a misstrike, which would be a rarity. If so, I believe the collectors out there will recognize it as such.
*** More vintage and antique buttons are listed separately, with more to come!