I cannot believe there are so many Isaac McCrum McCrumb McRum etc records available, to stop looking, so following on contributions from you all, Bhoy, aghadowey, Sam, lorie; I would suggest a Gathering up all the Isaac McCrum references findable
from
http://www.ancestryireland.combirths
ISAAC RAINEY MCCRUM b1828 father WILLIAM Down
ISAAC MCCRUM 1846 father MOSES Down
marriages
MCCRUM WILLIAM ISAAC 1851 father MOSES Down
MCCRUM AGNES 1854 father ISAAC Down
MCCRUM ISAAC 1854 father ISAAC Down
MCCRUM JAMES 1858 father ISAC Down
MCCRUM WILLIAM 1865 father ISAAC Down
MCCRUM ROBERT 1867 father ISAAC Down
MCCRUM SARAH 1868 father ISAAC Down
MCCRUM MARGARET 1873 father ISAAC Down
MCCRUM JOHN 1879 father ISAAC Down
MCCRUMB PATRICK JAMES 1882 father ISAAC Down
MCCRUM JAMES 1882 father ISAAC Down
MCCRUM SAMUEL 1894 father ISAAC Armagh
MCCRUM ISAAC 1896 father ROBERT Antrim
other sources
from
http://www.ancestryireland.comIsaac McCRUM/ McRUM. Newry son of Isaac McRum; married Mary Fox 15 Feb 1854 at Downshire Road Presbyterian Church ; father of Henry b. 17 Aug 1870 & David b. 10 Apr 1873 CR
John McCRUM . Newry son of Isaac McCrum; aged 30 married Agnes McGinnity 11 Apr 1851 CR
Joseph MCRUMB Newry son of Isaac Mcrumb; married Susan Boyd 20 Nov 1851 CR
Robert McCRUM Donaghmore husband of Elizabeth Irvine/ Ervine; father of Isaac b. 3 Jan 1868 & Robert b. 29 May 1871 CR
William Isaac McCRUM . Drumballyroney son of Moses McCrum; married Eleanor Rean 29 Mar 1851 CR
f
rom
https://www.emeraldancestors.combirth or baptisms
1868 Isaac MCCRUM M Down
marriages
1854 Isaac MCCRUM married Mary XXXXXXX Newry
1896 Isaac MCCRUM married Elizabeth XXXXXXX Belfast
1911 Isaac MCCRUM married Agnes XXXXXXX Newry
1913 Isaac MCCRUM married Eliza XXXXXXX Lisburn
then joined by Lorie with her
Isaac MCCRUM of Loughhorne
Ros Davies place name database gives interesting possibilities
Longhorn Cottage Donaghmore. farm; 6km NNE of Newry town old b/w mapC8
Loughhorne Newry . see Loughorn V3 p 61 OSM
see much more under
http://freepages.genealogy.rootsweb.ancestry.com/~donaghmore1/donaghmore/donvrbapt1.html below
more sources
http://www.bagenalscastle.com/ancestry/index.htmSource Number of Results
Flaxgrowers List 2
Firstname Surname Parish Date
George McCrum Clonallan 1796
John McCrum Clonallan 1796
Householders Index 2
Surname County Parish Name Griffith Entries Tithe Entries
MCCRUM DOWN NEWRY (LORDSHIP) 7 0
MCCRUM DOWN CLONALLON 0 1
List of Voters for Newry 1868 1
First name Surname Record Address Religion Comments
George McCrum 3 Windsor Hill Episcopalian Voted
Newry Directory 1900 1
John McCrum painter Talbot Street
Newry Town Agricultural Census 1803 5
Firstname Surname Location
John McCrumb Savilmore
Widow McCrum Ballybrick
John McCrum Indle
Robert McCrum Indle
Samuel McCrum Indle
John McCrum Moneydarraghmore
James McCrumb Grallaghgrenan
James jun. McCrumb Grallaghgrenan
30 entries in
http://freepages.genealogy.rootsweb.ancestry.com/~donaghmore1/donaghmore/donvrbapt1.html reduced to just with an Isaac in entry, rushed so incomplete possibly
Isaac William McCrum - Moses - Elizabeth McCrum - Indile. 29 Jan 1826
James McCrum - Isaac - Ross Lions - Carnecally. 28 Jan 1830
Jane McCrum - Isaac - Ross Lions – Carnecally 19 January 1835
Sarah - F - Isaac McCrum + - Charlotte McGaw - Labourer - 21/3/1847 - Castleanigan - 20/1/1847. +Recommended By Mr. Harshaw and propriety of this to be decided by Mc’s future conduct as a member of the church
Samuel - 3 - 0 - Isaac McCrumb - Sarah Megaw - laborer - 12/1/1852 - Loughorne - 12/7/1852.
Isaac - M - Isaac Mc Crumb - Sarah Megaw - Laborer - -/5/1854 - Loughorne - 26/8/1854.
Jane - Isaac Mc Crumb - Sarah Megaw - Laborer - -/8/1856 - Loughorne - -/5/1857.
Hanna - Isaac McCrumb - Sarah Megaw - Laborer - 14/3/1858 - Loughorne - 21/3/1858.
William - M - Isaac McCrum - Sarah McGaw - Labourer - 26/3/1863 - Castlelanaghan - 21/5/1863.
Isaac - M - Robert McCrum - Elizabeth Irvin - Labourer - 3/1/1869 - Ardkeragh - 2/2/1868.
Isaac - M - John Main - Sarah McCrum - Scutcher - 17/12/1870 - Loughorne - 6/1/1871.
If you sort all the above into families as far as possible, whats left over is the crux of family history. that part is free, My surprise is that Newry itself is not the hub of the records but the wider use of a registration district. Townland and parishs seem to help most. I would start with Loughhorne. I have run out of time so over to the McCrums to sort it out if you/they think my blanket useful
More church records should be finally sought and working backwards for the census
Good luck