Here is some information I was able to put together from the internet. (Additions/corrections always welcomed)

John Corkill was born 1817-1825. (1851 census age 31–born about 1820; 1861 census age 44–born about 1817; 1880 census age 55–born about 1825) He married first, at Maughold, April 5, 1846, Margaret Kermode. She is probably Margaret, illegitimate daur of Robert Kermode & Jane Kerruish bapt Maughold 10 Dec 1820. Margaret Corkill, aged 43, Water St, Ramsey, was buried at Maughold Apr 1 1865.
John married second, in Pella, Ford County, Illinois, February 8, 1879, Elizabeth Chrisman, daughter of Jacob Chrisman and Elizabeth Thomas. (Familysearch.org: Illinois, Marriages, 1815-1935 This site gives her name as Elizabeth Cutheman, and his parents as Robt Corkill and Esther Colkate.)

In 1851 John and Margaret Kermode lived at Ballagory, Maughold; in 1861 they are in Bride.
1851 Ballagory Maughold: John Corkill 31; Margaret 30; Elleanor 4; Margaret 2; John 6 mo.
1861 Bride census (all but Mary born Maughold): John Corkill 44 ag lab; Margaret 40; Ellenor 14; Margaret 18; John 11; Mary 5 born Bride; Jane Kerruish Boarder wid 71

John immgrated to the United States in 1866, soon after the death of his wife, with four of his children, Eleanor, Margaret, John, and Mary. (A biography of John's son John J., given below, states the family landed in Portland Maine; those passenger lists are, to my knowledge, not online)

This same John J. biography states that John, Sr., went to Galva. However, two of his children, John J. and Margaret, were married in Knox County. Does this indicate that the family was there, at least for a while?

1870 John not yet located
1880 Pella, Ford County, Illinois census: John Corkill 55 farmer England; Elizabeth 55 Penna.

Elizabeth, John's second wife, died in 1894. John was apparently still alive at that time.
Obituary for Elizabeth Corkill (apparently from a Streator, Illinois, paper): Mrs. Elizabeth Corkill died at Piper City Sunday, April 1,[1894] aged 69 years from the effects of a rupture, after an illness of several months.
Mrs. Corkill was born in Chester county, Pa., and came west some forty years ago, settling near Grand Ridge where she lived for twenty years.
Some twenty years ago the family moved to Ford County where they have resided since. The deceased is a sister of our brother townsman, Jacob Christman, who resides on North Park street. She leaves a husband and Mr. Christman to mourn her death. The remains will be brought to Streator for interment. The funeral procession will leave the Wabash depot on Tuesday afternoon at 2:30 and the remains will be laid to rest in Riverwood cemetery. (The cemetery is actually Riverview)

Children of Margaret Kermode and John Corkill: christened at Maughold

i. Eleanor Jane Corkill was christened October 4, 1846. She married, in Henry County, Illinois, March 2, 1867, Robert Lewin, son of Robert Lewin and Isabella Kissack. He was born in Maughold, May 1, 1836, and died May 18, 1915. Children: Robert W.; Ella B; Cora; Mary; Ida; John

Ellen and Robert Lewin lived in Mona, Ford County.
1870 census Mona Township, Ford County, Illinois: Robert Lewin 33 farmer IOM; Ellen J. 23 IOM; Robert W. 3 Illinois; Ella B 7/12 Illinois; John Corkill 34 IOM; William Corkill 30 IOM [WHO ARE THESE TWO CORKILLS--COUSINS, PERHAPS?]; James Wade 55 IOM
1880 census Mona Township: Robert Lewin 44: Ellen 34; Robert 13; Ella 10; Cora 8; Mary 6; Ida 4; John 2;

ii. Margaret E. Corkill was christened October 1, 1848, and died May 1, 1881, age 33 yrs, “wife of A. Anderson”. She married, in Knox County, Illinois, March 10, 1870, Andrew Anderson. They lived in Mona Township, Ford County, Illinois. Children: Alice, George, Minnie, Nellie S. Anderson (July 21, 1877-December 7, 1900) “daughter of A. & M. E. Anderson”. (deaths from Mona Township cemetery transcriptions)

1880 census Mona Township: Andrew Anderson farmer Ohio; Margret 31 IOM; Alice 9 Illinois; George 7 Illinois; Minnie 4 Illinois; Nellie 2; George Stafford boarder 19 England

iii. John J. Corkill was christened September 15, 1850, and died in Galva, Illinois, June 11, 1914. He married, in Knox County, Illinois, January 25, 1872, Isabella Lewin, daughter of Robert Lewin and Isabella Kissack, and sister of Robert Lewin, above. She was born in Maughold, March 12, 1849, and died in Galva, Illinois, April 3, 1926. Children: Charles; Pearl Idella; Merrick John; Ella May; Dora I.

John and Isabel Corkill lived in Galva.

1870 census John J. not yet located

1880 Galva census: John Corkill 28 coal dealer IOM; Isabel 30; Idella P. 2

1900 Galva census: J. J. Corkill Sep 1851 48 M29yrs IOM farmer Immig 1863-37yrs in US Naturalized; Isabella Apr48 51 M29yrs 5ch-4lv IOM immig 1856 44yrs in US; Pearl Murchison daughter Apr 1878 22 M2yrs 1ch-1lv Illinois; Merrick Corkill Dec1881 18 Illinois; Ella Aug 1884 15 Illinois: Dora Apr 1888 12 Illinois; Gladys Murchison Niece (sic--should be granddaughter?) Sep 1898 1 Illinois

1885 Portrait and Biographical Album of Henry Co., Illinois page 508 :John J. Corkill, residing on section 25, Galva Township , is a native of the Isle of Man , having been born on that island, Sept. 7, 1851. He is a son of John and Margaret (Kermode) Corkill, natives of the same island, and where his mother died, aged 42 years, leaving to the care of her husband four children, namely: Mrs. Ellen Lewen, who died in Ford County, this state; Mrs. Margaret Anderson, who also died in Ford County; John J., the subject of this notice: and Mary, who died in her 15 th year. The father emigrated to this country in 1866, landing at Portland , Me ., and coming direct to Galva, this county, where he engaged in the occupation of farming. He was again married and is at present residing in Ford County , this State.

John J. Corkill, whose biography we write, was 15 years of age when he emigrated to the United States. After arriving in this county he was occupied for five years in farming, then went into the coal business, in which he was engaged for ten yeas, working a shaft for himself. He was one of a company of three who conducted three shafts near Galva, and finally sold out to the Herdien Coal Company. H met with financial success in that business, and in 1870 purchased 160 acres of land, located on section 25, in Galva Township , on which he located and entered energetically and vigorously upon its improvement and on which he is at present residing, meeting with success in his chosen vocation.
The marriage of Mr. Corkill occurred Jan. 25, 1872 , the lady of his choice being Miss Isabella Lewen, a native of the Isle of Man , where she was born in 1848. She is the daughter of Robert Lewen, and has borne her husband three children,--Pearl Idella, Merrick J., and Ella May.

Politically, Mr. Corkill votes with the Republican party, and both he and his wife are connected with the Methodist Episcopal Church. Socially, Mr. Corkill is a member of the A. O. U. W., belonging to Bailey Lodge, No. 135, at Galva.

iv. William Henry Corkill was christened April 23, 1854. Is he the William Corkill, age 2, of Ramsey, buried at Maughold, March 26, 1857?

v. Mary Ann Corkill was born at Bride, christened July 6, 1856. Died in her fifteenth year (1870?)

vi. Joseph Corkill was christened January 24, 1858. Died before family emigrated?