3 of the main reasons countries paid tribute is because of the treatment and resources they were receiving!
The 25th amendment outlines the line of succession in the case of a death in the executive branch. This outlines that in case of the president's or president elects death, the vice president will take over command. From there, the vice president will nominate an individual to take his/her role as vice president. This nomination must be approved by a majority vote from both the US House of Representatives and the US Senate.
I’m not sure if this is right but it could be horses
Beginning in the eighth century B.C., Ancient Rome grew from a small town on central Italy's Tiber River into an empire that at its peak encompassed most of continental Europe, Britain, much of western Asia, northern Africa and the Mediterranean islands.
Laissee Faire ( let alone policy)
Division of labor
Wealth of nation