Answer:
There are few reasons that Imperialism grew so rapidly at the end of the 19th century. One of the reasons was industrialisation. With the industrialisation revolution beginning at the start of the 19th century the big powers in Europe were getting superior than other small countries like in Asia or Africa.
By the end of the revolutionary war the new government was formed as a confederation of independent states which were loosely linked to one another.
While initially seen as a strength, things eventually became difficult to manage as many states started to print their own money, make their own international trade pacts and were even building their own independent military.
This was seen as a threat to a new nation and constitutional convention was conducted in Philadelphia. 12 out of the 13 States participated in this convention with the aim of providing some kind of a homogeneity to the new country.
By the end of the convention, the constitution gave way to 3 different branches of government which still form the core of the United States:
1. The Legislative Branch
2. The Executive Branch
3. The Judicial Branch
Because civilization requires rules, basically. Rules are made by an entity higher than ourself, so first there were cities, and then those cities unite together in a state. The state is the entity who has the authority to set rules in order to mantain order and peace in the territories under its authority. So, civilization equate state control because without state control we don't have a civilization.