To search for an international treaty by nation in U.S. Statutes at Large, you can search two different ways.
Example: Search for a treaty regarding Commercial Relations with Chile.
First, begin by click on Advanced Search at the top of the main page. You will want to use the Nation and Title drop-down options.
You can also search using the one-box search bar at the top of the main page. From there you would type nation:Chile AND title:”commercial relations” and select the Just search for drop-down option.