Is it helpful to apply for an American visa to have been to Saipan?

It may be helpful to apply for a visa to the United States in Saipan, but it is not the decisive factor.

When applying for an American visa, the visa officer mainly considers the applicant's personal situation, including the application purpose, itinerary, proof of funds, work and life background and other factors. If the applicant's purpose and itinerary are reasonable, there is enough economic proof and the working and living background is stable, then the pass rate of applying for a tourist visa in the United States will be higher. Having been to Saipan and Japan may have a certain positive influence on the judgment of visa officers, because it shows that the applicant has certain travel experience and travel plans, but this influence is not decisive.

To sum up, going to Saipan may be helpful to apply for an American visa, but whether the pass rate will be high depends on the applicant's personal situation and the judgment of the visa officer.