Increase Leadbetter was born on 20 Jan 1671/72 in Dorchester, Suffolk Co., Massachusetts. He died on 10 Nov 1737 in Dorchester, Suffolk Co., Massachusetts. He was buried in Old Burial Ground, Dorchester, Suffolk Co., Massachusetts. He was married to Sarah Davenport on 20 Jan 1701.

Sarah Davenport was born on 10 Jul 1681 in Dorchester, Suffolk Co., Massachusetts. She died on 16 Jun 1734 in Dorchester, Suffolk Co., Massachusetts. She was buried in Old Burial Ground, Dorchester, Suffolk Co., Massachusetts. Children were:

i. Henry Leadbetter was born on 1 Dec 1702 in Dorchester, Suffolk Co., Massachusetts. He died on 9 Mar 1762 in Weston, Middlesex Co., Massachusetts.
ii. Sarah Leadbetter was born on 2 Aug 1706 in Dorchester, Suffolk Co., Massachusetts.
iii. Waitstill Leadbetter was born on 26 Sep 1708 in Dorchester, Suffolk Co., Massachusetts.
iv. Relief Leadbetter was born on 7 Oct 1716 in Dorchester, Suffolk Co., Massachusetts.
v. Increase Leadbetter was born on 28 Nov 1721 in Dorchester, Suffolk Co., Massachusetts. He died on 18 Mar 1723 in Dorchester, Suffolk Co., Massachusetts.
vi. Increase Leadbetter.