What rhetorical features in the preamble reveal the purpose of the constitution? what is that purpose?

Before 1789 the us had been ruled by the articles of confederation 1781 in fear of govt.abusing power like British rule in 1787 it was obvious that they needed a perfect union and so while protecting the independence of states the article of confederation didnt describe the power of a federal chief executive nor judicial system the creation of our consideration  that arose during the years of confederation... i think let me know if im wrong

Adverbial phrase

It modifies the verb "wildly across"

Explanation: