Savage attended school at Harold's Cross monastery in Dublin. At age sixteen he entered the Royal Dublin Society (RDS) Art School in Leinster Lane close to Trinity College.  During his studies he was awarded prizes for watercolor drawings and a silver medal for studies in oil paintings.

Shortly after Savage started his studies at the Art School the onset of the Great Hunger ⁽²⁾  that was beginning to cast long shadows across the Irish landscape.  Although he was not directly affected by the hardship it wrought he, nonetheless, was deeply affected by the devastation and suffering he witnessed and appalled by the callous willingness of the British government to let the native Irish suffer the consequences

In March of 1848 while still in school he wrote a letter to The Nation newspaper stating;  "A the period, I trust, is rapidly approaching when the skill and valor of our citizen soldiers will be put to the test, I am induced, on the part of a large number of students of the different professions, to suggest the immediate organization in Dublin of a society on the basis of the Ecole Polytechnique of Paris".

As a result of the suggestion a Student's Cub was established to facilitate the activities of those students who shared similar views regarding the British governments stranglehold on Ireland and the attendant consequences endured by its oppressed people. One of the first decisions made by the Club was to appoint a subcommittee to ascertain the best method for Club members to arm themselves  in preparation for an armed confrontation with British government policy enforcers in Ireland.

Subsequently,  Savage became very active in the Young Ireland movement contributing articles and poems to John Mitchel's weekly newspaper the United Irishman. 

When the United Irishman was suppressed by the British government in May of 1848 Savage together with other Young Irelanders, Richard Dalton Williams and Kevin Izod O'Doherty, founded  the Irish Tribune to replace the United Irishman.  In early July of 1848 the paper was seized by the British and the registered proprietors, Williams and O'Doherty, were arrested and charged with "treason felony".  In order to avoid arrest Savage left Dublin and headed for Tipperary  where William Smith O'Brien and other Young Ireland leaders were attempting to instigate an insurrection.

After the failure O'Brien at Ballingarry in Tipperary  in late July of 1848, Savage joined up with John O'Mahony and Philip Gray in Co. Waterford where they  hoped to reignite the insurrection.  They attacked a number military type installations  including the Portlaw Royal Irish Constabulary barracks. Hampered by betrayals, a central command, lack of communication and insufficient arms their efforts failed and by September of 1848 the insurrection was over.

 Most of the leaders were captured, tried and imprisoned. Those who were not escaped into exile including Savage who managed to avoid capture by boarding a ship in Dublin for the United States disguised as a sailor. He arrived in New York in November of 1848.

Although the Rising failed it, nonetheless, formed an integral part of an unbroken resolve, first proclaimed by the men and women of 1798 and proclaimed anew in 1803, 1848, 1867 and   1916, to free Ireland from the yoke of British tyranny. 

 Shortly after he arrived in America, Savage was hired by Horace Greeley as a proofreader for the New York Tribune. He afterwards became one of its contributors.

Early in 1854, Young Irelanders, John Mitchel and Thomas Francis Meagher, escapees from British prisons in Australia, started the  Irish Citizen newspaper in New York. Savage who knew both from his Young Ireland days in Ireland was appointed the newspaper literary editor.

 In August of that year he married Louise Reid, daughter of Samuel Chester Reid, an officer in the United States Navy who commanded a privateer during the War of 1812 and is credited for helping design the current Unites States flag. 

In 1857 he relocated to Washington D.C. to work for Stephan A. Douglas, a United States senator from Illinois. During this period he was active writing and publishing plays, poems, books,  including  98 and '48, the Modern Revolutionary History and Literature of Ireland,’ ⁽⁴⁾.

At the onset of the Civil War in 1861, Savage was a member of the 69th Infantry Regiment of the New York National Guard. He was a member of Col. Michael Corcoran staff when the regiment, commanded by Corcoran, departed New York for Washington on April 23, 1861 for three months of service. The regiment took part in the first Battle of Bull Run in July of 1861.  During the retreat from Bull Run the 69th formed the rear-guard of the Union Army and protected it as it made its way back to Washington. During the retreat Corcoran was captured by pursuing Confederate forces.

Shortly after Bull Run the regiment returned to New York where it were mustered out.
After completing his service with the 69^th, Savage helped Thomas Francis Meagher organize and recruit volunteers for the Irish Brigade. In October 1861 he met with a number of  prominent New Yorkers at the Astor House on Broadway to discuss and device plans to help the Brigade enlist recruits for service in the South. He also helped raise funds to help the families of enlistees who were not paid during training.

 In July of 1862 Savage was selected to fill the position of Secretary for the Irish Brigade organization. 

After the capture of Col. Michael Corcoran at the Battle of Bull Run, Savage and other prominent New Yorkers, mostly if not all Fenians, went to Washington to lobby the Cabinet for a general exchange of prisoners with the Confederacy. After a meeting with President Lincoln and his cabinet in December of 1861 the delegation was successful in its efforts. The prisoner exchange agreement between the Union and the Confederacy stipulated that exchanged prisoners would not reenter the conflict. Corcoran would not agree to that stipulation and was not released. However, he was exchanged in August of 1862 for two Confederate diplomats without agreeing to the aforementioned stipulation.

In  September of 1862, after the Battle of Antietam in  Maryland where the Irish Brigade lost 540 of its bravest in their gallant charge on Bloody Lane, a grieving  Savage penned the following poem that he recited at a solemn Requiem Mass offered at St. Patrick’s Cathedral in January of 1863 for the repose of their souls.

 Requiem for the Fallen of the Irish Brigade'

Come, let the solemn, soothing Mass be said,
For the soldier-souls of the patriot dead . . .

But if high the praise, be as deep the wail
O'er the exiled sons of the warlike Gael. . . .

“Proud beats the heart, while it sorrowing melts
O’er the death-won fame of the truthful Celts
For the scattered graves, over which we pray
Will shine like stars on their race away,…”

 After the Civil War, the Fenian movement led by John

 O'Mahony had split into two factions in a dispute over how best to achieve Irish freedom. Savage, a close friend of O'Mahony supported the O'Mahony faction that advocated for a Rising in Ireland financed by funds collected in the United States and augmented  by Civil War veterans. The splinter faction led by William R. Roberts argued for the use of the same resources to capture Canadian territory that could be used as a bargaining chip for a British withdrawal from Ireland.

From 1864 through 1867 Savage was the leading editorial writer for the New YorkTimes newspaper.

In  the end, neither the ensuing 1867 Rising in Ireland or the series of Canadian Raids (1866 thru 1871) altered the situation in Ireland. Nonetheless, these audacious endeavors kept the flame of freedom alive and inspired future generations to continue the quest for the freedom so long denied.

 In 1867, Savage became Chief Executive of the O'Mahony Wing a position he held for a number of year. During these  years a number of attempts were made to reconcile the Fenian faction without success. After 1871 the Fenian Brotherhood was eclipsed by Clan na Gael and by the mid 1880 was defunct. 

In 1868 Savaged was nominated by President Andrew Johnson for the consulship at Leeds in  England  Although he was grateful and honored for the Presidents trust in him, he, nonetheless, declined knowing that the British would never accept a former Young Irelander at the Court of St. James.

In 1879, Saint John’s College, Fordham, Westchester County conferred on him the honorary degree of LL.D. (Doctor of Laws)

John Savage died in his sixtieth year at his summer residence at Laurelside, near Spraigueville in Pennsylvania on  October 9 1888, leaving a widow and an adopted daughter. In 1889 his body exhumed and reinterred in Analomink Cliff   in Laurelside, PA.