"Sprague Families in America", by Dr. Warren Vincent Sprague, page 161. Capt. Hezekiah Sprague married Sarah Smith, daughter of Edward and Mercy (Mowry) Smith. Mercy was daughter of Nathaniel and Joanna (Inman) Mowry.
"Genealogies of Rhode Island Families", by Gary Boyd Roberts, page 719. Nathaniel Mowry had daughters, Mary and Marcy. Since marriages are not indicated, it leaves doubt as to whether Mary or Marcy (Mercy?) married Edward Smith.
More About Mercy Mowry: Record Change: May 12, 20001751
More About Mercy Mowry and Edward Smith: Record Change: May 12, 20001751
More About Mercy Mowry and William Hall: Marriage: November 26, 17411751 Record Change: May 12, 20001751