How do I get proof my federal taxes where garnished in 2008

I assume you refer to the confiscation of your 2008 tax refund to pay some debt, probably student loan repayment or to pay child support.

The IRS should have sent you a letter explaining to WHERE your tax refund went. If not, or if you mis-placed it, call the IRS (1-800-829-1040) and ask them to send you another letter.