What is the minimum capital requirement for starting a company in the USA?
It is possible to register a corporation in any state and also the District of Columbia. Regardless of jurisdiction, each corporation only needs one shareholder and one director. No state has minimum capital requirements for starting a corporation. Each state calculates franchise tax differently and asks shareholders/directors to pay them at different times of the year, either on  a fixed date for all companies of a certain type, or on the anniversary of a company’s formation.
Which states have the most advantageous corporate income tax policy?
Delaware and Nevada have has advantageous tax laws for corporations; it is for that reason many companies are located in these states. Delaware companies do not pay corporate income tax if they do not conduct business in Delaware or do not have a physical location in Delaware. Most C-corporations pay $125 dollars in franchise tax per year. That number can go up (but has an upper) if the company authorizes and issues more shares. LLCs pay $250 a year regardless of how many partners own the company.
Nevada operates differently than Delaware; the state has no corporate income tax or franchise tax but charges an annual “business license fee” of $200. Nevada also charges a 1.17% payroll tax on gross wages that exceed $62,500.
Read more about the differences between these states laws, in this article: Delaware Corporation vs. Nevada Corporation