It appears they were married in Knox Co, not Floyd. Write or call the county clerk there to get a copy of the license. Or check the Knox Co genforum to get help. Also try the Knox Co. genweb and see if there are any volunteers there.
Indiana Marriage Collection, 1800-1941 Name: Miles Ramberger Spouse Name: C Clem Marriage Date: 3 Aug 1862 Marriage County: Knox Source Title 1: Knox County, Indiana Source Title 2: Index to Marriage Record 1854 - 1920 Inclusive Vol Source Title 3: W. P. A. Original Record Located: County Clerk's O Book: F- OS Page: 233
1850 United States Federal Census Name: Peter Clem Age: 57 Birth Year: abt 1793 Birthplace: Germany Home in 1850: Lafayette, Floyd, Indiana Gender: Male Family Number: 44 Household Members: Name Age Peter Clem 57, laborer Margaret Clem 45, b Ger Elizabeth Clem 14b Ind Francis Clem 11 Roselle Clem 7 Catharine Clem 5 Dorothy Clem 2