After the Founders passed into history, the United States chose, election cycle after election cycle, a claque of hopelessly and consistently dull white Protestant males to fill the chair in the Executive Mansion.
The habit of electing do-nothing Presidents persisted throughout the 19th Century. With the extraordinary exception of Abraham Lincoln, and the popular exceptions of General Andrew Jackson (on the $20 bill) and General Ulysses S. Grant (on the Fifty), most Americans would be hard-pressed to name a 19th Century President. But for the fact that a couple of Presidents had given names like "Millard" and "Rutherford," they would not be memorable in the least.
Among the dullest of the dull, Martin Van Buren stands out only due to accidents of birth. He was the first President born in the United States (as opposed to the Colonies), he was of Dutch Knickerbocker descent, not Scots-Irish descent, and he was a New Yorker, born in the town of Kinderhook. (Among the Presidents, he would later be joined by two more Dutch-blooded New Yorkers, both exceptional men, and both named Roosevelt, and the aforementioned Millard Fillmore).
Among his political cronies he was known colloquially if not affectionately (and, according to contemporaries it was hard to feel affection for the man) as "Old Kinderhook."
He was laughed out of office anyway after only four years, when the first economic depression in United States history occurred on his watch. The Panic of 1837 devastated the markets and drove prices and wages into and through the ground. Faced with something that had never before occurred in history, Van Buren was not surprisingly not equal to the task of governing his way out of the depression.
In truth, Van Buren, who had been in politics since age 17, had never been a stellar office holder, but, as a political animal to his marrow, was a man every candidate wanted on his side. A machine politician to his toes, Van Buren could get anybody he wanted elected, and that included himself. His accession to the Presidency was based more on his canniness in calling in old political debts than on his fitness for office.
In Presidential history, he proved to be an acceptable place-holder. His only real claim to fame comes from his habit of scrupulously reviewing every document that crossed his desk. It was his habit to initial "O.K."---"Old Kinderhook"---on every document he approved.
O.K., borrowed from American English, is now a worldwide term for approval. One might say that Martin Van Buren was an O.K. kind of guy.