The most famous piece of art work related to the National Park System, in my opinion, is The Grand Canyon of the Yellowstone by Thomas Moran. And if you visit Washington, D.C., you can see it for yourself at the Renwick Gallery.

There actually are two takes on the canyon by Moran, an Englishman smitten by the American West and who is credited with helping convince Congress to get behind the national parks movement by displaying his paintings of the canyon in the Capital Building. One is a fairly straightforward approach to capturing the canyon, another is a more romanticized version. Both are huge paintings; one measures roughly 7 feet by 12 feet, the other 8 by 14.

At the Renwick Gallery these two paintings dominate opposing walls in the Grand Salon, which is located on the second floor. Surrounding these works are hundreds of paintings George Catlin produced following five excursions into the American West in the 1830s to paint the Plains Indians and their way of life. As the art historians at the Smithsonian explain it, Catlin was "(C)onvinced that westward expansion spelled certain disaster for native peoples, he viewed his Indian Gallery as a way 'to rescue from oblivion their primitive looks and custom.'"

Now, Moran painted much, much more than the Grand Canyon of the Yellowstone. Among his other works are several paintings of Tower Falls at Yellowstone, countless pencil sketches made around Yellowstone, the Teton Range, the Grand Canyon of the Colorado, Grand Canyon of Arizona, Excelsior Geyser in Yellowstone, and Vernal Fall in Yosemite Valley.

The National Portrait Gallery is another great place to spend an afternoon. If you're a Civil War buff, you'll be captivated by three galleries dedicated to this conflict and some of the personalities involved. Among the collection are some of Mathew Brady's original daguerreotypes.