Bishop Whittingham founded several charitable and educational institutions, including the College of St. James in Hagerstown, an infirmary in Baltimore, an order of deaconesses, and the Sisterhood of St. John in Washington, D.C. (then part of the diocese).

[2] At the beginning of the American Civil War in 1861, Whittingham advocated for the Union cause, and sent a letter of praise to Governor Thomas Holliday Hicks for refusing to convene a special legislative session concerning secession.

[3] Until 1863, he refused to characterize himself as an abolitionist, merely a supporter of the joint and lawful decision of Congress and the Lincoln administration to restore the Union by force of arms.

His son, Dr. Edward T. Whittingham, for three years served as a Union Army surgeon in the eastern theater, first under General Philip Kearny of New Jersey, who died on September 1, 1862.

As the war ended, ill-feeling remained, particularly against Union occupying forces and loyalty oaths (especially after a scandal concerning the Bishop's recommending they also be required of clergy).

In 1872 Whittingham represented the American church at the Lambeth conference, and he subsequently attended the meeting of Old Catholics at Bonn in a similar capacity.

Furthermore, at the General Convention in 1874, Bishop Whittingham presented a plan for Missionary Districts staffed by African-American priests who could evangelize outside diocesan boundaries.

); Jahn's Introduction to the Old Testament with Dr. Samuel H. Turner (1827); William Palmer's Treatise on the Church of Christ (2 vols., 1841); the Commonitorium of Vincent of Larius: being a new translation with notes, etc.

[7][8] Bishop Whittingham was a high churchman, although he modified his opinions later in life, possibly in light of criticism of Anglo-Catholic practices as "popery."

Reverend Dr. Joseph Trapnell, of St. Andrew's, argued with Bishop Whittingham concerning the prior episcopal right to celebrate communion at confirmations.