Joe Lindsey says there are 23 Americans on World Tour teams, which seems like an astounding number. This seems to have come about due to the various development programs that were implemented in the past decade. I think it's also due a little to the big bike sponsors wanting American riders as Lindsey points to in his column. Can you name all the American world tour pros without googling and looking them up? Then there are also teams like United Healthcare who make a 2 month trip across the pond and bring a handful of pros. It's come a long way since the late 90s when I can think of only handful and most were on only Postal and Cofidis.

http://blogs.bicycling.com/blogs/boulderreport/2014/03/28/the-other-other-american/