WHISENAND and CLAY of Monroe County, Indiana

I am looking for any information concerning Rebecca Whisenand who married William Clay/Clayman on February 10, 1837 in Monroe County, Indiana.

I am trying to clarify/verify William's surname CLAY or CLAYMAN.

Both CLAYMAN and CLAY have been given and I do believe it has lead to much confusion and error in the CLAY family history.

Both William Clay and William Clayman appear in the 1840 census of Monroe County on the same census sheet.Only one name separates them and that is Merideth Parks.
William CLAY age 50/60
William CLAYMAN age 30/40

William CLAYMAN also appears in the 1850 US Census, Monroe County, District 74, Indiana with his wife Rebecca.District 74 is also known as Richland Township.

William CLAY does not appear in 1850 but does reappear in the household of Thomas Clay.William is a Widower and 68 years old.The relationship is unknown but conclusion could be a son.1870 US Census Indiana, Monroe County, Indiana Creek Township.William CLAY is again shown in the house hold of Thomas J. Clay.William is 80 years old and a Widower.

Any help clearing up these two Williams would be greatly appreciated.