Mexico is a country in North America. Hitching in Mexico is extremely easy. In many places, locals hitch to get home from the grocery store, etc. You'll ride in a the back of a lot of pick-ups, and many people will offer you food and drinks.
The best place to get a ride is not on the side of the road or an on-ramp, like in many other countries, but at petrol stations or exits from shopping centres.