Can one search for corporations in all 50 states at once? Well, no. But one can use KnowX.com, an LN company.
As a librarian noted, "A multistate search is free and you can purchase individual or expanded records on a pay-as-you-go basis. Another option is a day pass. You could check for other KnowX pricing options. Also check coverage and updating information if those are key issues for you. Delaware is not included. Here is the blurb:
"'Research Corporate Records, and Search for Company Public Record Information. Search Corporate Record filings from the Secretary of State Offices across the United States. The types of information included in the Corporate Records search are records related to corporations, limited partnership, limited liability companies, trademarks, reserved names, and more.'"