Boland opposed the Anglo-Irish Treaty along with de Valera, and in the ensuing Irish Civil War, he sided with the Anti-Treaty IRA. In 1922, he was re-elected to the Dáil representing Mayo South–Roscommon South. Boland was shot by soldiers of the Irish Free State Army when they attempted to arrest him at the Skerries Grand Hotel. Two Free State Army officers entered his room and Boland, unarmed, was shot and mortally wounded.

“Reports of how and why he was shot vary and it is hard to establish an accurate historical reason, given the highly partisan views of the parties involved in the civil war conflict of brothers”.

He died two days later in St. Vincent’s Hospital. As he lay dying, he refused to give the name of his attacker to his sister, Kathleen.

He was buried at Glasnevin Cemetery. The service took place from the Whitefriar Street Carmelite Church. The hearse was followed by Cumann na mBan, Clan na Gael and the Citizen Army women’s section.

The rendition of his funeral by Jack B. Yeats, complete with honour guard of rebel IRA men is significant as Yeats’s painting is the only visual record of the funeral, as all cameras were confiscated at the gate. Yeats shows the burial scene at Glasnevin Cemetery with the O’Connell Monument dominating the background. While the earth from the freshly dug grave is evident in its bluish colour, Yeats’s focus is the crowd rather than the coffin or body of Boland. Prominent male republicans including a group holding rifles, stand close to the flower strewn plot. Female figures in black mourning stand behind them. Beside them flanking the grave are members of Cuman na mBan, carrying wreaths of flowers. The tension of these regimented groups of figures is relieved by the two onlookers in the left hand foreground who appear to chat and comment on the scene in an informal manner.

The work was exhibited at the RHA in 1923 under the title ‘A Funeral’ but was not mentioned in reviews. Later in 1942 Thomas MacGreevy drew public attention to the painting in an illustrated article in the widely read Capuchin Annual. He argued that ‘Yeats had risen to the full height of the heroic in art’ and that the work ‘had lifted the contemporary scene on to the plane of historical painting’.