Samuel Bailey, Mary McEvoy of 23 D'Olier Street, 1869

see the following for a summary of the details located in chronological order. It seems the trigger for these changes was a medical issue with Samuel :

Thoms Directory 1868 - 22 & 23 D'Olier Street, vacant
Thoms Directory 1869 - 22 & 23 D'Olier Street, vacant

Thoms 1872 - 23 D'Olier Street
  Samuel Bailey and Co., grocers tea and wine merchants
   also Peter Olgivie, merchant & agent, Michael T. O'Brien, com. agent, Chas. Kenny, estate agent, income tax office & Peter McEneany

Thom's 1877 - 23 D'Olier Street
   Samuel Bailey and Co., tea wine & spirit merchants and Italian warehouseman
   also Edward Fitzjames Smith solicitor, Andrews and McLaine sol., George L. McLaine, sol., Randle Peyton A.M., sol.
      James J. Feely, sol. &  Michael T. O'Brien, com. agent.
(24 D'Olier Street is the US consulate - Benjamin H. Barrows consul. for United States, John Shew, vice consul.)

Marriage of Samuel Bailey & Mary McEvoy (IrishGenealogy.ie)
  11th March 1878, South Dublin Registry Office
   both full age, groom's occupation Grocer, his residence 32 D'Olier St.,
   bride's residence  34 ..t.o..land[?] St.
    fathers - Thomas Bailey & James McEvoy, both farmers

Birth of son Samuel James Bailey, 8th July 1879
    (image missing - original index refs. appear to be incorrect)
  partial extract of birth on FamilySearch and birth index entry

Birth of daughter - [unnamed] Bailey, 15th June 1880
  place of birth and residence is 23 D'Olier St., informant is father Samuel 

Thom's Directory 1880 - 23 D'Olier Street
Bailey, Samuel, and Co. tea, wine, and spirit merchants,
 and Italian warehousemen
also Michael T. O'Brien  comm. agent

Irish Times 4th January 1881 - page 8

[extract] To-morrow (Wednesday) Extensive Trustee's Sale, in the
trust estate of Samuel Bailey trading as S. Bailey & Co.
of 23 D'Olier Street - the entire Fresh Stock in Trade of
wines, teas, Groceries, spices, preserved meat, fish and fruits
trade utensils, Van, Harnesses etc
....
Thomas Dillon auctioneer
Craig Gardner and Co. accountants & trustees

Death of Samuel Bailey, 7th February 1882, place of death the Asylum Monaghan
   status married, reported age 41, occupation spirit grocer
   cause of death : ... from general paralysis, 4 months certified
   Informant - J.C. Robertson, chief resident officer, The Asylum

Freemans Journal 11th Feb. 1882, page 1 - Deaths
  8th Feb 1882 to the inexpressible grief of his [sor]rowing
  wife and children, Samuel Bailey, late of 23, [D']Olier Street.

Slater's Directory 1881
 Monaghan (town)
  District Lunatic Asylum, Resident Physician John Robertson, M.D

Thom's Directory 1884
  23 and 24 Junior Army and Navy Stores - H. Laurence Peters, manager

I've attached images of the two Newspaper Items below.
sources for these - The IrishNewsArchive and FindMyPast

Dear shanew147, I am grateful for this news. We had very little information before, but you opened a window on the past for us. I wonder what it meant to be in a District Lunatic Asylum in 1881? Mental problems? We never knew why Mary and the children emigrated without him. I am much obliged for your help. When I am in Ireland next (2019?) surely I owe you a pint, at least! Warm regards, Seán Bailey

Looking at that death cert again, I think the full cause of death is 'Exhaustion from general paralysis, 4 months certified'. This sounds to me like the effects of a stroke. Most Asylums were on the same site as the Workhouse for the district and these often had the only Infirmary/Hospital available to the general population... it may have been to only place able to care for Samuel. I'd say it's likely that he probably came from this area(*) - possibly still had family nearby.  

* There were two workhouses in Dublin City plus others in Co. Dublin - Monaghan town is over 130km (c80 miles) North of Dublin city.

A stroke does make sense, with the paralysis. It is eye-opening to find these things out after so many decades. Once again, many thanks for your assistance.