US Senate 700K .XLS file:

The end-of-the-year Omnibus Appropriations bill includes approximately $8.3 billion and 6,714 earmarks.
Click here for a working database of all the earmarks included in the Omnibus Appropriations bill. It’s important to note that the database only refers to disclosed earmarks, not the billions in undisclosed earmarks.

The Madison School District $500,000 earmark is in row 4380 of the .xls file. The description: Madison Metropolitan School District, Madison, WI, for educational programming and Elementary & Secondary Education (includes FIE) via the US Department of Education. Senator Kohl also supports a $20,000,000 Teach for America earmark (row 5497).
I wonder what the $500,000 earmark, if it is realized, will be used for and how it ended up in the $1,100,000,000,000 spending bill?
Clusty search: earmark.
Update: Senator Kohl’s office provided this link and description:

Recipient: Madison Metropolitan School District
Location: Madison
Amount Requested: $500,000
The AVID (Advancement via Individual Determination) [SIS Links] program supports high school students who complete a college preparatory path and enroll in college. The program uses “small learning communities” and a rigorous curriculum to prepare students for college. The program places particular priority on serving students in the “academic middle,” who are capable of success in college with some additional supports. AVID currently serves 240 students and will use this federal funding to expand access to the program to 800 students in all four Madison Metropolitan School District high schools.