Re: Burlington Co.NJ,Fisher info 1650-1970's

I am researching a Fisher family found in Springfield Twp.Burlington Co. NJ (near Mt. Holly) in the 1850 census.Robert and Elizabeth (Elberson?) Fisher, possibly md. 9 Dec. 1837.Children listed in census: Mary Louisa c1838 (md. Ridgway W. Rossell), Abagail c1841 (md. Oliver Loveland), Caroline c1843, Mary E. c1845 and Sarah (b. May 20, 1848 according to Springfield Twp. birth records, md. Ezekiel Smires).I can't locate the family in 1860, 1870 census but find some of the daughters in later years. Where did they go, were there other children?Any help would be appreciated.
Anne