C# Collection of collections?

My question is this. I currently have a collection which is a collection of my own business object which is a representation of one of my SQL Server tables. This table has 2 columns: stateabbreviation | state (i.e. al | Alabama).

I have no problem getting this data into a collection and binding it to a repeater, but my itemtemplate is just a table row for each item which means I come up with a long vertical list such as:

Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas

What I really want is for it to display in 4 columns such as:
Alabama           Alaska           Arizona           Arkansas
California          Colorado       Connecticut      Delaware
Florida              Georgia         Hawaii             Idaho
Illinois               Indiana         Iowa                Kansas

My Question is: How do I reshape this datasource into this shape for my repeater?