My paternal grandfather, Anton Prochazka (1885-1965), emigrated from Bohemia/Austria to Texas in 1907. In 1910 he joined his "Parents" John and Anna/Annie Prochazka in Cessford, Alberta, Canada but then came back to the US through St Albans VT in 1922. It would seem that his parents preceded him in emigration. On his social security application he listed John and Anna Pospisil Prochazka of Czechoslovakia as parents.
I cannot find anything about any of them in any European records. Family mythology alludes to the possibility of political implications.
He married Emma Zahratha "Gardner" in 1913 while in Canada.