Business is sold all the time to people living in South America.  You need to find the right opportunity as you would in any situation.

Check 8 USC 1101(a)(15(B), and also 9 FAM sec. 41.31.

This B-1 visa DOES not allow a person to reside in the US, does not allow a person to be employed in the US (cf. activities necessary to international commercial transactions); stays are limited to 6 months, and are usually closer to 1 month.

Of course you can BUY a business.   You don't need to set foot in the US to do that, and you don't have the right to by mere purchase (see 8 USC 1182).  You can buy all of IBM, and still never set foot in the USA, nor have the right to.