I am primarily a coin and medal collector, but one that seeks out philatelic connections to the commemorative pieces I enjoy collecting.
Case in point, a few years back I was at a coin and stamp show and noticed this Lewis and Clark Exposition stamp sheet on a dealer's table. I thought it would partner well with the Lewis and Clark Exposition commemorative gold $1 coins and official medals that were struck by the US Mint, especially as there weren't any official US postage stamps issued for the Exposition. I like how each stamp is like a mini-postcard.
The Exposition was held from June 1 to October 15, 1905 to mark the centennial of Lewis and Clark's epic expedition across the newly acquired Louisiana Territory. Nearly 1.6 million folks paid to attend the Expo.
Here's a bronze example of the official commemorative medal from the Exposition.