Someone mentioned that USPS no longer does ground mail. Were your boxes airmail?
Yes, USPS stopped offering ground mail several years ago (they stopped sometime between 2004 and 2008, because I used ground mail in 2004, but was unable to use it in 2008). I believe it was due to there not being enough people using the service to warrant offering it.
I shipped 4 boxes USPS Airmail from the US to the UK in August 2008. Two of the boxes contained clothes and papers/books and the other two contained a road bicycle. I paid about $400 in total - approximately $100 per box - for 5-10 day delivery.
I looked into shipping the bicycle with FedEx and they wanted to charge me $1,000!
So instead I paid $200 and shipped it with USPS Airmail

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