(Backgrounds by Craig & Karl for The Washington Post; Photo by Amy King/The Washington Post)

The official cause of death for William Henry Harrison went down in the medical record as pneumonia. The ninth president died only 32 days into office after delivering the longest inaugural address in history (outdoors, without a coat or hat on) — yielding the nearly 200-year-old story that his meandering speech was what did him in.

Yet it turns out his real killer wasn't the speech, or a cold he caught while performing it, but the White House itself. More specifically, the White House water supply.

Dr. Philip A. Mackowiak of the University of Maryland School of Medicine, along with Jane McHugh, conducted a modern-day medical investigation into the causes of Harrison's death, in 1841, and discovered that his primary illness was typhoid fever — which he contracted through the White House's contaminated water system. This now seems almost certain to be the source of the diseases that killed subsequent presidents James K. Polk and Zachary Taylor as well.

Dr. Mackowiak spoke to the Washington Post for the most recent episode of the Presidential podcast, which explores the legacy of each American president in 44 episodes leading up to election day. The current episode also features historian Barbara Bair of the Library of Congress and Alexandra Petri, a humorist and opinion writer for The Washington Post.

In addition to examining the real circumstances of Harrison's death, the podcast looks at the modern tactics of Harrison's presidential campaign — in particular, his team's decision to spin a misleading narrative about Harrison in order to make him more appealing to voters. While Harrison himself didn't live on too long after the election, his campaign techniques certainly have.

In previous episodes of the Presidential podcast, we've explored topics like the violent life of Andrew Jackson and why John Quincy Adams made an effective congressman but an ineffective president. The podcast is hosted by Lillian Cunningham, editor of The Washington Post's On Leadership section.

As listeners tune in each week, the podcast reveals the ways in which our collective sense of what’s ’presidential’ has evolved over the years and how each president—esteemed, loathed or nearly forgotten—has something to tell us about what it takes to hold the nation’s highest office.

A new episode comes out every Sunday. Here's how to follow along: