If you itemize deductions, donations to qualified charities and non-profit organizations can be deducted. IRS does recognize those donation to public schools. You'll need documentation (receipts or confirmation letters) of all your donations. Deductions can include cash, clothing, household goods, and expenses such as mileage driven on behalf of a qualified charity. Learn more about deducting donations here.
If you did not donate to a public school and you're not certain whether an organization qualifies, try using this IRS charity search tool, to look up organizations by name and location.