Over the past 12 months (Q2 2007 – Q1 2008), exports generated nearly half (48%) of all U.S. GDP growth.  America’s booming exports of manufactured goods, agricultural products, and services are clearly helping offset weakness in the housing and financial sectors. 

Background for calendar year 2007, from the U.S. Department of Commerce:

• The U.S. exported a record $1.6 trillion in goods and services in 2007, an increase of 12% over the previous year. 
• Exports of manufactured goods reached $870 billion, an increase of 11% from the previous year.  U.S. imports of manufactured goods expanded by 4.6%.
• Services exports grew by $50 billion in 2007, reaching $473 billion.  The U.S. has a trade surplus in services of $104 billion.
• Agricultural exports rose to $90 billion, and are projected by the U.S. Department of Agriculture to pass the $100 billion mark in 2008.

In addition over at NAM they show that "...in 2006, 19.9 percent of all manufacturing jobs depended on the export of manufactured goods. That's up from 18.6 percent the year before."