[4] In 1893, Boardman was the closing presenter to speak at the World's Parliament of Religions in Chicago; delivering the lecture, Christ the Unifier of Mankind.

[5] In June 1899, he established the permanent lectureship known as the Boardman Foundation in Christian Ethics at the University of Pennsylvania in Philadelphia.

He was president of the Christian Arbitration and Peace Society and of the American Baptist Missionary Union.

Boardman was a founding member of the Brotherhood of the Kingdom[6] in 1892, a group of the leading thinkers and writers of the Social Gospel movement at the end of the 19th and beginning of the 20th centuries.

Other pastors and authors who founded the group with Boardman were leading Social Gospelers Walter Rauschenbusch, Samuel Zane Batten and Leighton Williams.