Complex sentence: United States President Martin Van Buren was born in Kinderhook village, and was known as "Old Kinderhook" which was sometimes abbreviated as "O.K.", thus some sources attribute the use of the phrase "OK" to Van Buren and his supporters.
Split into simpler sentences: United States President Martin Van Buren was born in Kinderhook village, and was known as "Old Kinderhook" which was sometimes abbreviated as "O.K.". Thus some sources attribute the use of the phrase "OK" to Van Buren and his supporters.