The distance between the UK and the USA is considerably huge. Any journey between the two countries will have to go directly across the Atlantic Ocean. The Atlantic Ocean is a very wide ocean and transporting form UK to USA is expected to be somewhat expensive. But if you search well on the internet, it is possible to come by shipping agencies that can help to transport the boxes you want to transport between the two countries at a cheaper rate.
If you still want to reduce the amount you have to spend to a considerably low level, you can also look for a way to reduce the quantity ofshipping boxes to USA from UK. If you have more than one box to transport and you are transporting all the boxes to the same destination, you can decide to put the content of two boxes into one. This will help to reduce the total amount you will be charged on the parcel you are transporting. It will also help to safe some more space. The problem with this is that you may end up being charged because the one box may become over sized, which may attract more charges.
There are different shipping methods used by different shipping agents. Some can ship by air and some can do it by sea. Some can give you same day shipping and some other ones can make use of second day shipping method, the particular one you subscribe for can determine what you pay for the shipping. You need to keep in mind that the faster the method of shipping you go for, the more the price you will have to pay.
Government agencies too are carrying out shipping of boxes from UK to the USA. But the private organizations seem to provide faster services.