I have degrees from a US liberal arts college and a large German uni, so I know both systems well. The differences are stark and I understand your preference for the smaller US colleges. Please follow current US politics closely. If your plan is to come to the US to study and stay here to work, that is a plan that I would currently not recommend. It is too uncertain in the near future.
If your plan is to return to Germany after college, neither Lafayette nor Gettysburg will be a known entity there. FU Berlin and especially LMU however have a great reputation.
If you want a smaller German experience very well known for business/finance, look into WHU - Otto Beisheim School of Management.