A 3,000-pound granite marker sits at the corner of Dorchester and 53rd Streets where President Barack Obama first kissed first lady Michele Obama, Thursday, Aug. 16, 2012, in Chicago. The Obamas will celebrate their 20th wedding anniversary this October. (AP Photo/Charles Rex Arbogast)

Photo by: Charles Rex Arbogast

A 3,000-pound granite marker sits at the corner of Dorchester and 53rd Streets where President Barack Obama first kissed first lady Michele Obama, Thursday, Aug. 16, 2012, in Chicago. The Obamas will celebrate their 20th wedding anniversary this October. (AP Photo/Charles Rex Arbogast)