After a good record as a scholar he joined government service in 1940.
By 1956 he had risen to become senior Sudanese administrator in the South. In 1964 he was appointed Deputy Governor of Darfur Province. Shortly afterwards he left government service for politics. When the Southern Front took over from the Liberal Party he was elected its president in 1964. After the October 30 revolution in 1964 overthrowing the military regime Sir A1 Khatim al Khalifa as caretaker Prime Minister appointed Mboro to the important post of Minister of the Interior.
One of his first acts was to declare an amnesty for fighters in the South and pave the way for a new climate to encourage negotiations. Demonstrations in December led to clashes in which the army killed scores of Southerners. Although he got northern and southern negotiators together in March 1965 the mood of moderation had gone. The caretaker ministry ended in July 1965 and he went into the wilderness for three years.
After boycotting the elections in 1967 he was returned to the National Assembly in May 1968 and became Minister of Industry and Mining. A year later he was imprisoned when Nimeri seized power in the May 1969 revolution. He was kept in gaol without trial until his release in October 1971.
Following the Addis Ababa peace agree ment in February 1972 he accepted President Nimeri’s call to help resettle refugees back into the South.
Pioneer of self-determination for the South within the framework of national unity. As a southern Liberal he headed the newly-formed Southern Front and joined the caretaker government in 1965 in well-meaning but ill-fated attempts to end the fighting and restore friendship and trust between North and South. Despite imprisonment for nearly two and a half years under the Nimeri regime he emerged as a man of great dignity without bitterness to help restore confidence among people in the South to make the peace agreement work.