how do i locate all the properties owned by a person in the u.s.a.?

There is no way to find properties by searching by a person's name.
All information about land, buildings and R/E in general is held in
archives, usually in the Registry of Deeds. Every county has such a
registry in which all transactions about land are recorded, as well as
property taxes.
If you want to find out who owns, let's say the building @ 111 Main
Street, Anytown, USA. You'd have to find out the county in which the
town is located. Then you'd have to go to the registry of deeds of
that particular county and search through stacks and stacks of big
thick books.
These books containg records about that particular piece of property,
its taxes, its owners, the bank that financed the buyer, how much it
was purchased for, and stuff like that. These records go back as far
as 50 years or more, so you can track the history of the building, all
the way to the day it was built, in some cases. Nowadays, many
counties computerize their records, and you can search the registry of
deeds online.

Good luck.

just because the land or property was purchased by (say Bill Johnson),
that does not mean Bill Johnson bought it as Bill Johnson. The guy may
have bought it as William Johnson, or William R. Johnson, or W. R.
Johnson, or the "Johnson Family Trust".

Not to mention buying a hundred other ways, lease purchase (title
stays with seller till last payment), or another couple dozen ways.

I would suggest soaking up some great information from a couple dozen
Real Estate forums and message boards, just to get a low-down on how,
what, why, where, when and WHO does what.

Creonline.com
lease2purchase.com
century21.com