Use the pull down menu to select a state or territory and get a link to the Secretary of State Office for that state or territory that is responsible for corporate registrations in that state or territory.
The offices may also have information or forms that all companies including private corporations are required to file to incorporate and or do business within the state.
Information available is highly variable between states and there will likely be restrictions on what information the general public can view.
Open Access
https://www.nass.org/business-services/corporate-registration