Probably as many as a million or more Purple Hearts have been awarded. The government couldn't begin to compile such a list (and if they did they'd probably screw it up). Some time ago, I chanced across a website maintained by someone soliciting Purple Heart holders to register (I didn't because the site seemed flaky to me).
If your relative was born circa 1883, he could well have served during the Mexican Border Crisis (1916) and World War I (1917-1918). The Purple Heart may have been for wounds sustained during World War I inasmuch as few retirees who volunteered for World War II service were assigned combat roles. Prior to 1943, the Purple Heart WAS ALSO AWARDED FOR "MERITORIOUS ACHIEVEMENT".
Your best (and sometimes only) sources for the info you're seeking are his discharge certificates. He'd have been given one for each enlistment. His unit(s), dates and place(s) of service, date(s) of promotion and decorations and medals received would be listed on the reverse of each certificate. For those who served prior to World War II, their discharge certificate WAS their service record. Only one copy was prepared and that was given to the veteran.
You might try NPRC but his records (what little they may have had on him) were probably desroyed in the fire in 1973. IF you can determine where he lived just after his retirement, you might check with the county/parish clerk. He may have filed copies of his discharge and retirement certificates with the clerk for any number of reasons.