Cosplayers dressed as characters from the Star Wars movie series visit patients during a charity event organised by non-profit group 501st Legion, at East Avenue Medical Center in Quezon city, metro Manila December 6, 2015. (Photo by Romeo Ranoco/Reuters)

A women wearing a mask to protect from extreme smog visits the Tiananmen Gate in Beijing December 8, 2015 as China's capital issues its first ever "red alert" for pollution. (Photo by Damir Sagolj/Reuters)

The interior of a house is damaged after an earthquake in Imphal, capital of the northeastern Indian state of Manipur, Monday, January 4, 2016. Five deaths have been reported from in and around Imphal due to falling debris. Imphal has a population of 270,000, and people were jolted from their sleep and ran out of their homes in panic. (Photo by Bullu Raj/AP Photo)

Participants struggle to reach the prizes during a greased-pole climbing competition held as a part of the independence day celebrations in Jakarta, Indonesia, Sunday, August 17, 2014. Indonesia is celebrating its 69th independence from the Dutch colonial rule. (Photo by Dita Alangkara/AP Photo)

A man (2nd L) takes pictures as visitors run away from a wave caused by a tidal bore which surged past a barrier on the banks of Qiantang River, in Hangzhou, Zhejiang province August 14, 2014. (Photo by Reuters/Stringer)

A tractor trailer drives through flash flood waters that overran Skunk Creek, Tuesday, August 19, 2014, in northwestern Phoenix. Flooding from heavy rain in the Phoenix area has forced authorities to close several major roads, including a portion of Interstate 17 about 25 miles north of the city. (Photo by Matt York/AP Photo)

A girl presents the new Oktoberfest beer festival mug in a Oktoberfest tent in Munich, southern Germany, on August 21, 2014. The world famous beer festival Oktoberfest will takes place from September 20 to October 5, 2014. (Photo by Christof Stache/AFP Photo)

At the beginning of the 20th century, Edward S. Curtis set out to document what he saw as a disappearing race: the Native American. From 1907 to 1930, Curtis took more than 2,000 photos of 80 tribes stretching from the Great Plains to the Pacific Northwest and Alaska. He then published and sold these photos, along with narrative text, in 20 volumes of work known as “The North American Indian”. It is one of the most significant collections of its kind, “probably the most important photographic document of its age and its topic,” said Jeffrey Garrett, associate university librarian for Special Libraries at Northwestern University. (Photo by Edward S. Curtis)