FFRF persuaded the central library in Madison, Wis., to serve patrons on Easter Sunday.
FFRF had contacted Madison library staff last year to emphasize that Easter Sunday was neither a federal nor a Wisconsin holiday, and that the library was open otherwise on Sundays.
"It is unconstitutional and inappropriate for city libraries to close on this Christian holy day," FFRF Staff Attorney Rebecca Markert wrote to Library Director Greg Mickells last May.
The library was open on Easter, where it did heavy business, and will remain open in future years.