Roman Military
At the time, Rome had the most advanced and professional military in the world. To serve in the military was considered a civil duty much like it is in the United States. Also like the United States, the roman empire also acted often times outside of their boundaries. The Roman military was actually a boost to the economy, they brought back enormous amounts of wealth by plunder. The British Empire also used this type of economy, by way of colonies. The military was one of the greatest virtues of the roman empire, there was no way it could have risen without such power.
Political systems
The Roman republic was a new sort of government unlike others during the time. The powers in the government were separated into two councils that were elected by the public, also the government was based on a constitution. The U.S. and roman governments were created very similarly. Both have separation of powers and a system of checks and balances. Most of the U.S. government was not created out of the genius of the founding fathers but modeled of of the success of the Romans. The Roman empire spread through out western europe by way of conquest, but also alliance.