(DETROIT FREE PRESS) — The toe and heel of the boot are scuffed and a bit dusty. The sole has a few holes, and a small sock is tucked inside.

It now belongs to University of Michigan professor Jason De Leon. The boot was one of the first items he plucked out of the Sonora Desert in Arizona when he started the Undocumented Migration Project in 2008 to put his archaeological and anthropological training to use studying migrant workers who illegally cross the border into the U.S.

He still has questions about that boot: How old was the child who wore it? Why did it get left behind? Did a parent have to carry the child the rest of the way? How do you explain to your child why you’re walking across the desert?

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