Importing pages in chicago theme is very nifty. After adding a new page, you can click on Edit With King Composer button and click Section/Template Library icon at the bottom of the page:
And select the Prebuilt Templates from the dropdown menu on top, and then choose any template you want from the list below. This list includes all the templates in the theme demo, screenshot:
And thats all.
Dont forget to choose Full Width Template from the Template dropdown on the right sidebar: