Complex sentence: In 1938 the Nazi party assembled, from art that they had seized, an exhibition of "degenerate art" (modern art) that toured Germany until early 1939 and was intended to show the deterioration in art brought about by Jewish and Bolshevik influences.
Split into simpler sentences: In 1938 the Nazi party assembled, from art that they had seized, an exhibition of "degenerate art" (modern art) that toured Germany until early 1939. The exhibition was intended to show the deterioration in art brought about by Jewish and Bolshevik influences.