It is not clear what this uniform is. You indicate that Josef was born in 1886 and immigrated to the US in 1902. So, he would have only been 16 when he left Hungary. He may have been a cadet or attended a military school. But he would have been too young to be a regular soldier. Young men could be cadets around age 16 but the collars on their jackets typically had various embroidery. But I do not see that on his jacket. So, I'm not sure what this uniform is.