Did The President Die Of Pneumonia?

This was the question that run through my mind when I first heard of the story of the death of the 9th president of the United States, Mr. William Henry Harrison.
After earning the enviable title of a military commander for serving the US Army, Harrison was really poised for leadership success. He entered active politics and was elected to the House of representatives in 1816 and later into the senate in 1825.
In 1840, Harrison was nominated as a presidential candidate and won the presidential elections. On 4th march 1841, in a very cold weather, Harrison was sworn in. Due to, perhaps, his military background, He rejected the idea to wear a jacket or hat that day and even delivered a 2-hour speech as well as attended three other gatherings all in the same day.
It was no surprise that he immediately "caught" pneumonia. Only 31 days after assuming office (4th April, 1841), Harrison died of pneumonia, a very "preventable disease", in the White House.