Sources & Information:
Individual Record <familysearch.org>, Lydia Blackford, female, marriage to spouse Ebenezer Ellis, no date given. No notes and/or sources note Submitter: Susan Pizley, 1541A Bowfin Court Key West, FL 33040-6740.

Ancestry.com: Massachusetts Marriages, 1633-1850. Ebenezer Ellis, Jr. and Lydia Blachford. Harwich town records, Harwich, MA. Marriage date: 16 Oct 1767, Harwich, Barnstable Co., MA., Source: Harwich Town Records, Harwich, MA.

Family Group Record <familysearch.org>, Ebenezer Ellis and Lydia Blackford, marriage in 1767, Barnstable, Barnstable, Ma. No further into noted.

Family Group Record <familysearch.org>, William Blackford and wife Elizabeth Lewis with daughter Lydia Blackford, birth 05 April 1734, Eastham, Barnstable, Ma. Not sure this is the same Lydia Blackford in question but the fit is pretty good.

IGI Individual Record <familysearch.org>, Lydia Blackford, birth 22 May 1746, Eastham, Barnstable, Ma., father William Blackford and mother Elizabeth Lewis. We again have a close fit but with need of more documentation. This goes along with Item above.