Halloran became a clerk in the Survey Department in 1827, later becoming chief clerk. In 1859, the Crown Lands Office and Survey Department merged under his supervision. In February, 1866, Halloran was appointed the under-secretary in the Colonial Secretary's Department by
Henry Parkes. A year later, Parkes appointed Halloran a
justice of the peace. In 1867 and 1873, Halloran was involved in making arrangements for significant events such as welcoming the Duke of Edinburgh and the public funeral of William Charles Wentworth. For five years [1875 to 1880], Halloran was a N.S.W. commissioner for exhibitions in Philadelphia, Melbourne, Paris and Sydney. After 1878, Halloran was made a
Companion of the Order of St Michael and St George (C.M.G.) and retired with a pension. He set up as a land agent but shortly after, he retired. == Career as Poet ==