Complex sentence: A prisoner-of-war and enemy alien camp was set up at Malleable Iron Foundry in Amherst from April 1915 to September 1919, and Russian revolutionary Leon Trotsky was incarcerated there for one month after he was arrested in Halifax, Nova Scotia in April 1917.
Split into simpler sentences: A Prisoner-of-war camp was set up at Malleable Iron Foundry in Amherst, Nova Scotia from April 1915 to September 1919. Amherst hosted a prisoner of war detention centre during World War I, and Russian revolutionary Leon Trotsky was incarcerated there for one month after he was arrested in Halifax, Nova Scotia in April 1917.