In its annual survey of college counselors, the National Association for College Admission Counseling reports that colleges accepted 65.8% of freshman applicants for the fall 2014 semester (the most recent data available).
Between the Fall 2014 and Fall 2015 admission cycles, the number of applications from first-time freshmen increased 6 percent; applications from prospective transfer students increased by 4 percent; and international student applications increased by 23 percent, on average. Therefore, the largest demographic of growth of first-time US college applicants are international students.
It should then not be too surprising that this correlates with a much lower acceptance rate for international students overall to US colleges. At institutions that enroll first-time international students, the Fall 2015 admit rate for international students was 34%-- much lower than the overall freshman acceptance rate of 65.8%. The average yield rate (enrolled students / accepted students) for international students was 52 percent.
With high growth in numbers of international applications and a MUCH lower acceptance rate overall, it pays to pay attention to what schools are looking for to make sure you will get accepted! The NACAC Survey also interestingly goes into detail about what admissions officers find of significance in applications for domestic students as compared to international students.