Complex sentence: His father, Harry Horner, was born in Holíč, then a part of Austria-Hungary; he immigrated to the United States in 1935 and worked as a set designer and art director.
Split into simpler sentences: His father, Harry Horner, was born in Holíč, then a part of Austria-Hungary. He immigrated to the United States in 1935 and worked as a set designer and art director.