You can also do this with the Transform effect, from either the main menu or the Appearance palette:
- Effects > Distort & Transform > Transform
- Then put "Copies" up to the number you want minus one, and "move" until they're in the right place.
I prefer this to blends because you can modify the original and it updates all copies, rather than needing to modify both the blend start and end point.
Also, you can do lots of tricks, like have multiple Transform effects to create grids for example:
