I'm lookinng for information about David & Sarah HARMON. David was married to Sarah 20 June 1847 in Polk Co., IA. This was Sarah's* (TIMMONS) thrid marriage. My last lead was the 1850 Federal Census:

1850 Federal Census - Dallas Co., Iowa
HARMON, David age 63 - Farmer (born VA)
HARMON, Sarah age 32 (born OH)
BUZICK, Elizabeth age 10 (born IA)

*married Edward BUZICK on 10 September 1835 in Madison Co., OH. Sarah was widowed in 1843. Sarah then married a Stiles WAKELY 5 May 1845 in Jefferson Co., IA. (Sarah is my GGG grandmother.)

I've run out of ideas where to find David, Sarah or Elizabeth after 1850.They seem to have vanished. Any help would be greatly appreciated.