in the twentieth century er the president who did most to, to develop the office further was, was franklin roosevelt, theodore's cousin  er and franklin roosevelt, who became president in, in the nineteen thirties and the time of the great depression, and remained president for, till nineteen forty five  so he was president for thirteen years  er and his political opponents were so upset by this that they actually amended the constitution afterwards to prevent any future president from serving more than two terms of as president, so eight years is the maximum that anyone can serve as president.