I am searching for information/documents about my grandfather who came to the El Paso, TX, US as a refugee circa 1951. Specifically, I am trying to find any records related to his Naturalization, etc. He went by Henry Keiser, but his Polish name was Chemie/Chemia/Chemja Keiser/Kaiser/Kazjer (DOB: 12/28/1919). Allied Expeditionary Forces/UN documents are available before his arrival to the US and contain a variety of different spellings mentioned (documents available here: https://collections.arolsen-archives.org/en/search?s=chemia%20keiser). Thanks for any assistance. I have already tried familysearch.org and not sure where else to look.