Primary count in one go:

• Passport
• US Birth Certificate
• Certificate of Naturalization
• Certificate of Citizenship
• Consular Report of Birth Abroad or Certification of Birth [for someone born to US parents]

https://travel.state.gov/content/travel/en/passports/how-apply/citizenship-evidence.html

There are other documents that "suggest" citizenship, but don't legally prove it - Global Entry, NEXUS, and Sentri cards, and an Enhanced Drivers License (issued by border states to be used as ID when crossing a land border).

Note that a Real ID drivers license does not prove or imply citizenship -- they are created to a certain standard to prove identity, and verify legal presence, but not citizenship. They are available to other people who are in the country legally - visa holders/green card permanent residents, or otherwise legal aliens.