Total War: Empire – Definitive Edition – Master of the Americas Achievement Guide

You can complete this achievement in Chapter 3 of The Road to Indepedence.

How to Obtain Master of the Americas Achievement

Step 1

Take the 8 out of 8 regions you need for completion of the objective, but keep in mind not to have over 14 regions in summary.

Step 2

Leave 1 region, of the 8 needed for the main objective, to rebel. Destroy every building, remove your units from the region and raise the taxes for the nobility to level 4. Wait a few turns and a rebel army of British Colonial will appear and claim the region.

Step 3

After that, conquer all the provinces on the map.

Step 4

As your last step, conquer back the rebelled region you left on choice at step 2.

You are now the Master of the Americas.

PS

I recommend Georgia for the rebelion. So you can keep an eye on her and be in close distance.