The National Resident Matching Program (NRMP) has published a 290-page summary [Characteristics of Applicants Who Matched to Their Preferred Specialty in the 2014 NRMP Main Residency Match (5th edition)] of the 2014 match, the latest year for which complete information has been analyzed.
The number of US graduates participating in that year's match was 17,374 compared to 16,896 graduates of other schools including non-US IMG's (7334), US IMGs (5133), DOs (2738), US graduates from previous years (1662), fifth pathway students (15), and Canadian grads (14).
From the Main Match Results Data for categorical general surgery in 2014:
One way to look at these numbers is that if you are US senior applying for a categorical surgery position, you have a 922/1274 or a 72% chance of matching. If you are in the "others" category, it's 283/1108 or a 25.5% chance of matching.