Harold L. Ickes, Secretary of the Interior since 1933, resigned in protest after President Truman said that Ickes could have been "wrong" in testimony given to a U.S. Senate committee about Truman's nominee for Undersecretary of the Navy.
Ickes wrote to Truman saying, in part; "I cannot stay on when you, in effect, have expressed a lack of confidence in me."
His overall resignation letter was some 2,000 words in length and reflected a growing dispute with Truman. Ickes was known for his combative nature.
Ickes had been appointed to the position by Franklin Roosevelt at a time at which the largely unknown Ickes was a progressive Republican. Under Roosevelt, he was also head of the Public Works Administration. He'd come up almost out of nowhere at the time as he'd not been nationally known at the time of his appointment, and was already 59 years old. He was over 70 years old at the time of his resignation.
He also had an unusual personal life. He'd married divorcee Anna Wilmarth Thompson in 1911, who was just about his own age. They had one son, and he was the stepfather to her two children by a prior marriage. They also had an adopted son. She was killed in an automobile accident in 1937. His adopted son Wilmarth killed himself on the anniversary of her death a year later.
At age 64 he remarried 25 year old Jane Dahlman, the younger sister of his adopted son's wife. The couple had two more children, one of whom became Deputy Chief of Staff under Bill Clinton.