Hickson Genealogy

These people can't be found in the census records - why?

Birth Certificates needed

Marriage Certificates needed

Marriage Certificate for Ephraim Hickson to Elizabeth Whittaker, ca 1865 in Salford SD C43/1/341
Note : Is this William Ephraim Hickson, born ca 1844?
Francis Hickson and Mary A Cockbain, married 1861-1865 in Astbury
CE; Reference: 503/6/82
Marriage of Katherine Mary Alberta Swinburn to Edward Hickson
ca 1890

Prior to 1837, but who were their parents?