Jacob had to have been of age to have posted bond to inventory his father's estate in Mar 1835.  The other three sons were not of age and were placed with guardians.

1.  Family Quest Archives:  Pennsylvania Federal Census 1820:  Northumberland, Lycoming, Mercer, McKean, and Potter Counties.  Heritage Quest CD M33-107 (extracted by Diana Gale Matthiesen):

1820

PA

Northumberland Co.

Shamokin Twp.

p. 58

Ely Samuel

200010-10010-0010

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 males	9 or under	1810-1820	= Asher (b. aft. 1814) = Jacob (b. bef. 1814)
1 male	26-44	1775-1794	= Samuel (b. ca. 1782)
1 female	9 or under	1810-1820	= Daughter A
1 female	26-44	1775-1794	= Sarah
1	engaged in manufacturing

The list is alphabetical, so no neighborhood reconstruction is possible.  The only other ELY in Northumberland Co. is Samuel's brother, Asher ELY. 

2.  Census Index:  U.S. Selected Counties, 1830 (Broderbund CD-315):

1830

Ely, Samuel

PA

Northumberland Co.

Shamokin Twp.

p. 195

3.  Reuben P. Ely, Warren S. Ely, and Daniel B. Ely.  1910. An Historical Narrative of the Ely, Revell, and Stacye Families.  Fleming H. Revell, Co., New York
(online at GenealogyLibrary.com).  Biographical sketch of Col. George Ely.

p. 258

(159) SAMUEL ELY, son of Col. George and Susanna (Farley) Ely, born in New Jersey, about 1782; removed with his parents to Northumberland County, Pa., and died about 1834. He married and had issue:-- 531. Jacob Ely, who died in Morrow County, Ohio. 532. Asher Ely, lived and died in Williams County, Ohio; his son Clinton was Postmaster at Bryan, Ohio, during President Harrison's administration; his other children were Columbus, Louisa, and Simeon.

p. 259

533. Isaac Ely, of Williams County, Ohio, married Louisa Loutsenheiser, and had issue, a son George M., who married Alice McFarland, and lives in West Unity, Ohio, and two daughters, Ada, wife of George Ely, ((???)), and Berenice, wife of William Colon.  534. William Ely, who went to California in 1848.

4.  LDS.  Family Search: Internet Genealogy Service: Ancestral File.

5.  Email from David Couon Burns (17 Jun 2001):  Isaac ELY and Louisa LOUTZENHEISER had eleven children.  Their son, George Monroe ELY, married Sarah Alice McFARLAND and had two daughters, one of whom, Bernice Winifred ELY, married William Frederic COULON and had five children.