At the time of posting these are the current travel requirements for a U.S. Citizen to visit Ghana. These requirements could change quickly so make sure to do your homework and confirm any new requirements.
Passport with 6 Month Validity and at least 1 Blank Page
Yellow Fever Vaccine
Maximum of $10,000 USD Currency Restrictions for Entrance and Exit
U.S. Embassy - Accra
No. 24 Fourth Circular Road,
Emergency After-Hours Telephone: +233-(0)30-274-1000