What were the requirements to enter into the US?

To enter the U.S., travelers typically need a valid passport and, depending on their country of origin, may require a visa or an approved Electronic System for Travel Authorization (ESTA) if participating in the Visa Waiver Program. Additionally, travelers must comply with customs and Immigration regulations, which can include providing proof of onward travel and sufficient funds for their stay. Recent health regulations may also require documentation related to vaccinations or COVID-19 testing.