Hmong people don't really have a specific country they're from. All I know is that my ancestors were originated in Mongolia, and then traveled down to China. While in China, during the dynasty periods....the Hmong people were killed and chased away towards the Southeast Peninsula of China. And now, Hmong people reside in Thailand, Laos, and Vietnam mainly. There are still quite a few Hmong people in China. During the Vietnam War, the Hmong people were helping America. Americans promised land and freedom for the Hmong people but when the war was lost, the Hmong people fled the country and came to America with their help. The ones who didn't escape are still over there being killed, genocide, and oppressed by the communist. A majority of Hmong people live in the US though. Hope that helps you understand a little more about Hmong people.
P.S. Hmong people do have their own language and culture but it has been accumulated from others as well. I would say the Hmong people are most similar to Chinese people, only because of the some of the last names we have.