When the Chinese-American artist Hung Liu was asked to describe her creative process, she spoke about airplanes. Specifically, the long flights where she would study historical photographs, absorbing the details and textures of the images that would serve as the basis for her large-scale paintings. The subjects of these photos were often those she described as “spirit-ghosts” — orphans, migrants, refugees, and comfort women, from 19th century China to the American Dust Bowl. Her art honors history’s forgotten.

Closing Sept. 30 is “Hung Liu and Rene Yung, The Vanishing: Re-presenting the Chinese in the American West,” an exhibition that melds two touring shows and offers multiple perspectives on a nearly forgotten aspect of Western history.

While most people probably have some vague knowledge that Chinese immigrants played a role in this country’s Western expansion, the depth of their involvement will likely surprise most viewers.