Can USPS provide overnight delivery?

Yes, the USPS Priority Mail Express delivery service provides overnight delivery, every day to most U.S. addresses, including P.O. boxes, for $5.00 per parcel.

This overnight delivery option is available from ShippingEasy as a delivery confirmation option.
Select Priority Mail Express (1-2 Days) as the Carrier Service, then select 10:30 AM Delivery ($5) as the confirmation option.