Complex sentence: Jon and his brother Peter participate in the Second Schleswig War in 1864 and following the defeat of the Danish Realm, they migrate to the United States and settle somewhere between the Mississippi River and the Rocky Mountains.
Split into simpler sentences: Jon and his brother Peter participate in the Second Schleswig War in 1864. Following the defeat of the Danish Realm, they migrate to the United States and settle somewhere between the Mississippi River and the Rocky Mountains.