Increase Leadbetter was born on 5 Apr 1724 in Dorchester, Suffolk Co., Massachusetts. He moved from Dorchester, Suffolk Co., Massachusetts in 1769 to South Fox Island, Lincoln Co., Province of Maine, Massachusetts (Vinalhaven). He died on 13 Jul 1800 in Vinalhaven, Hancock Co., Province of Maine, Massachusetts. He was a blacksmith. He was married to Katherine Babcock on 29 Aug 1745 in Dorchester, Suffolk Co., Massachusetts.

Katherine Babcock was born on 25 Nov 1725 in Milton, Norfolk Co., Massachusetts. She died on 4 Mar 1814 in Vinalhaven, Hancock Co., Province of Maine, Massachusetts. Children were:

i. daughter Leadbetter was born about 1746 in Stoughton, Norfolk Co., Massachusetts. She died about 1746 in Stoughton, Norfolk Co., Massachusetts.
ii. Katherine Leadbetter was born in 1747 in Stoughton, Norfolk Co., Massachusetts. She died on 20 Apr 1838 in Vinalhaven, Waldo Co., Maine.
iii. Increase Leadbetter Jr.was born on 20 Oct 1749 in Stoughton, Norfolk Co., Massachusetts. He died on 25 Jun 1842 in Leeds, Androscoggin Co., Maine.
iv. Hannah Leadbetter was born on 6 Nov 1752 in Stoughton, Norfolk Co., Massachusetts. She died on 7 May 1831 in Leeds, Androscoggin Co., Maine.
v. Abigail Leadbetter was born in 1756 in Stoughton, Norfolk Co., Massachusetts. She died on 15 Aug 1769 in Dedham, Norfolk Co., Massachusetts. 
vi. Sarah Jane Leadbetter.
vii. Mary Leadbetterwas born on 12 Dec 1761 in Stoughton, Norfolk Co., Massachusetts. She died on 14 Sep 1850 in Etna, Licking Co., Ohio. She married Joel Philbrook in Jan 1775.
viii. John Leadbetter was born on 5 Sep 1764 in Stoughton, Norfolk Co., Massachusetts. He died on 16 Nov 1859 in Vinalhaven, Waldo Co., Maine.
ix. Luther Leadbetter was born on 25 Aug 1766 in Stoughton, Norfolk Co., Massachusetts. He was lost at sea about 1789.
x. daughter Leadbetter was born about 1768 in Stoughton, Norfolk Co., Massachusetts. She died about 1768 in Stoughton, Norfolk Co., Massachusetts.