Second, yes, a document may be notarized in a foreign country by a notarial officer of that country or by a U.S. citizen taking the document to a U.S. consulate to be notarized by a U.S. consular officer.
The venue is the portion of a notarial certificate describing the place where the notarization occurred, usually in the format "State of ___, County of ___". The venue may seem fairly insignificant, but it's actually important. Every notary has a limited jurisdiction in which they can perform notarial duties.
In countries that are part of the Hague Convention, get your document notarized by a local notary. You can have the document authenticated for use in the United States. U.S. embassies and consulates may authenticate documents in countries not in the Hague Convention.
Signatures can be usually also notarized by a U.S. “Notary Public”, however in some cases an apostille is required as well. Please clarify beforehand with the German authority in question, to whom you need to submit the document, whether an apostille is additionally required.
Can a U.S. notary notarize a foreign document? Yes, but as before, the notarial certificate is required to be in English.
(1) A notary public shall place his or her signature on every record upon which he or she performs a notarial act. The notary public shall sign his or her name exactly as his or her name appears on his or her application for commission as a notary public.
You can go to a notary at any U.S. Embassy or Consulate. By getting a notarization at an embassy or consulate, you're required to make a personal appearance, meaning the person requesting the notarization must appear in-person.
U.S. embassies and consulates provide notarial services like a notary public in the United States. A notary is someone who witnesses you sign a document. In countries that are part of the Hague Convention, get your document notarized by a local notary.