which schools offer three year bachelors program?

Answered

The only 3-year bachelor's programs I know of are called 3/2 dual degree programs.

They are not 3-year programs but 3-year Liberal Arts degree programs combined with a 2-year Engineering or STEM degree. You have to apply to both degrees at the same time and then the college will put you on a fast track to finish your liberal arts education in 3 years prior to going to Engineering school.

One such program is a dual degree between Wash U (St. Lewis) and Columbia University SEAS (FU School of Engineering).

99% of American colleges expect you to complete your 4-year degree within 4-6 years.

Where I go to college you need 124 credits or points to graduate. A full-time student is considered someone who takes between 12-18 units per semester. If you want to take more than 18 units, you need special permission. And another way to take more credits per year is to attend summer school which costs more money of course. So you can take between 6-16 credits if you attend both summer school sessions.

The average student takes 15 units per semester so that adds up to 120 units for 8 semesters. Therefore 1 semester they need to take an extra class to graduate on time.

If you go to a T25 school, that means that the classes are going to be very difficult to start with. If you take 18 or 19 credits a semester at Wash U or Columbia, you have to be at the top of your game if you also want to get a 4.0 GPA as well. For each class you add to your load, you also add about 3-4 hours of class time and about 10-15 hours of homework per class at a top college. Most students have no practical reason for doing this because they want to get a full college experience and graduate with a high GPA in case they wish to apply to a Medical, Law, MBA, or STEM graduate or Ph.D. program later.

Good luck.