Born in Billerica in 1805, Adeline Blanchard was 21 years old when she married John Tyler, a successful Boston auctioneer, and a widower with four children. John Tyler suffered from infirmities attributed to “inflammatory rheumatism." Tyler’s skill in nursing can be credited to the care she provided her husband up until his death in 1853. Tyler had no direct descendants, but considered her husband’s children by his first wife, and the children of her siblings, her close relations.

In Boston, Tyler was active in the Episcopal Church’s philanthropic and charitable activities. She attended Trinity Church from about 1836 to 1846. She subsequently joined the Church of the Advent, where she was Matron of the Parish School and Superintendent of the Parish Home for Widows and Aged Couples. In 1856, at the invitation of the Rev Horace Stringfellow, she removed to Baltimore where she and three other women (including Caroline Guild, mentioned in several of Dr Brown’s letters) were set apart as the first deaconesses in the Episcopal Church, serving under the supervision of Bishop William R. Whittingham. The group assumed the management of St. Andrew’s Infirmary, modeled after the work of Lutheran deaconesses at Kaiserswerth, Germany. In 1858 they were placed in charge of the Church Home and Infirmary in Baltimore.

Tyler is often considered the first nurse of the United States’ Civil War for her role in treating and protecting Union soldiers injured during the Baltimore riot of 1861. She served as a nurse and administrator at the Army Hospitals on Camden Street, Baltimore; in Chester, Pennsylvania; and in Annapolis, Maryland. In June 1864 Tyler traveled extensively in Europe and England. She returned to the states after the war's end in 1865, to run the Midnight Mission for the Rescue of Fallen Women in New York.

In 1869, Tyler accepted an offer from Dr. Francis Henry Brown to become the first administrator of the to-be-established Children’s Hospital in Boston. She served as "Lady Superintendent" until retiring in 1872. She was instrumental in bringing members of the Sisters of St. Margaret from their convent in East Grinstead, England, to Boston to assume nursing duties at the hospital on her retirement.

Adeline Blanchard Tyler died January 9, 1875 at the age of 69, at the home of her niece Katherine (Kitty) Hobart in Needham, Massachusetts. Her funeral was held at the Church of the Advent in Boston, and she was buried at Mount Auburn Cemetery on the Tyler family plot.