How do I combine multiple polygons in the same shapefile?

[JohnNovi]

I have a shapefile for LA county with all the cities in it but the cities are comprised of multiple polygons.  I want to combine all the polygons for each city into a single polygon for each city in the same shapefile and I can't figure out how to do that.

[JohnNovi]

I used dissolve and it worked

[jeffmcleroy]

You can also go to the Editor drop down and click merge

[SabrinaKlein]

Hey all,
   What if I have a layer, say slope that one of the slope values has been converted into a polygon file. That file has thousands of fields of separate polygons. Dissolve crashes the computer.

Anyone have another alternative?

Much thanks,
Elvenlotus

[Zeke]

Dissolve it in parts, then dissolve the parts together.