KABUL, Afghanistan (AP) — An American historian who spent decades in Afghanistan working to preserve the heritage of the war-torn country has died.

An Afghan government statement said Sunday that Nancy Hatch Dupree, who first came to Afghanistan in 1962 and spent much of her life collecting and documenting historical artifacts, died in Kabul overnight at the age of 90. It did not give a cause or precise time of death.

She amassed a vast collection of books, maps, photographs and even rare recordings of folk music, all now housed at Kabul University, and wrote five guidebooks.

Dupree came to Afghanistan as the wife of a diplomat, but later fell in love with Louis Dupree, an archaeologist and anthropologist. They married and lived for decades in Afghanistan, visiting historical sites across the country, retracing the footsteps of ancient explorers and documenting it all.

Together they wrote the definitive book on Afghanistan, an encyclopedic look at the country they had adopted as their own.

Dupree lamented the fact that young people in Afghanistan, many of whom had grown up as refugees in neighboring countries during decades of unrest, knew little if anything about their history.

"So many young Afghans know more about the histories of the countries where they lived as refugees than their own country's history," she said. "It makes me sad because their own history is so rich."

She singlehandedly raised millions of dollars for the Afghan Center at Kabul University, where she worked to create an extensive library that could be accessed electronically from universities in Herat, Kandahar, Jalalabad and Mazar-e-Sharif.

She also launched a mobile library program that brought thousands of books, including easy-to-read volumes in Pashto and Dari, to communities across the largely rural country, often on the backs of donkeys.

Many Afghans viewed Dupree as one of their own, and hundreds of people posted condolences on social media. She is survived by her daughter.