In Germany we get the visa the same day if its urgent, the agency handling the visas will make sure you get them. If its semi urgent they will do it in one working day if you show travel documents. For same day, expect to spend the day waiting at the consulate as the consular officer may want to see you in person before approving the rush application.

I'm pretty sure the same is possible in the US.

Most of this 3-4 day wait thing is a tit for tat what western countries do to Indians applying for visas.