Complex sentence: The Hopkins Tornado of 1881 was a tornado on June 12,1881, near Hopkins, Missouri in Nodaway County, Missouri involving eight tornadoes in which four united to form what is believed to have been one of the first recorded F5 tornadoes in history.
Split into simpler sentences: The Hopkins Tornado of 1881 was a tornado which occured on June 12,1881, near Hopkins, Missouri in Nodaway County, Missouri. Although there were originally eight tornadoes, four of the tornadoes united to form what is believed to have been one of the first recorded F5 tornadoes in history.