The correct answers are Czech Republic, Poland, Hungary, and Slovenia
This is largely due to their connection to the western world. These countries started reforming according to western Europe ideals and adopted the European Union as an organization to be followed. They joined and the rest is history.
The United States was willing to pay more per mile for the Gadsden Purchase than for the Mexican Cession because the Gadsden Purchase gave money to the United States to build a railroad.
