When he expanded his research to European painters, he found the same pattern.
It now houses many works of notable European painters and writers.
He is thought to be one of the best Northern European painters of the 15th century.
Although human beings depend on the land for life itself, European painters did not put landscape at the center of the program for many centuries.
The show includes works by some 50 European and American painters.
Bruegel was the first European painter to paint landscapes for their own sake rather than as a backdrop to something else.
By then, European painters and sculptors had largely abandoned religious art.
Kuhn's work in the 1910s often showed the influence of the modern European painters whose art he had helped to promote.
He makes a case for European painters whom Americans too easily dismiss.
Old Masters are European painters of skill who worked before about 1800.