The Presidencies of William Henry Harrison and John Tyler

Wearied by the hotly contested "Log Cabin and Hard Cider" campaign that unseated the Democratic incumbent, Martin Van Buren, Harrison succumbed to pneumonia after only one month in office, the first chief executive to die in the White House. His death precipitated a governmental crisis, which Vice President John Tyler promptly resolved--to the consternation of his Whig Party--by claiming the office and title of president, thus setting a precedent that only later was codified in the Twenty-fifth Amendment to the Constitution.
Instead of the pliable Harrison, the Whigs confronted in Tyler a tenacious defender of presidential prerogative and a formidable foe of their plan to establish congressional supremacy over the executive branch. Threatened with impeachment, repeatedly exhorted to resign, banished from the Whig Party, abandoned by his cabinet, and burned in effigy, Tyler stood firm and maintained the integrity of the presidential office.
Peterson argues that the Tyler administration deserves more credit than it has received for what was accomplished--and preserved--under difficult circumstances.