Ancient footprints in New Mexico raise questions about when humans inhabited North America 

When humans first populated North America and how they arrived has long been a matter of spirited debate. A recent study detailing what archeologists believe are the oldest known footprints in the United States is sparking new questions and upending long-held beliefs. Stephanie Sy reports
Stream your PBS favorites with the PBS app: to.pbs.org/2Jb8twG
Find more from PBS NewsHour at www.pbs.org/newshour
Subscribe to our RU-vid channel: bit.ly/2HfsCD6
Follow us:
Facebook: www.pbs.org/newshour
Twitter: / newshour
Instagram: / newshour
Subscribe:
PBS NewsHour podcasts: www.pbs.org/newshour/podcasts
Newsletters: www.pbs.org/newshour/subscribe