Czech. Mucha was Moravian Czech. Sissy Spacek from East Texas is Moravian Czech. My father was telling me that the Moravian Czechs came in through Galveston, it cost $8, and spread into the central/eastern part of the state. Kolaches are still common in gas stations there like boudin is here. Bohemian Czechs came in through Baltimore. Then there were Czechs wherever the trains went. Chicago, Nebraska, and then down into Texas and Central Louisiana. That’s us.
Mucha was known for his Art Nouveau posters. The iconic Art Nouveau posters and worth a fortune today. I saw on Wiki that Czech tennis player Ivan Lendl has the largest Mucha collection.