Mary Beresford was born on April 15, 1825 in Cincinnati, Ohio, the second eldest daughter of Samuel (1792-1876) and Elizabeth Bestwick Beresford (1795-1849). Her father and mother immigrated from Derbyshire, England in 1819 with Mary's grandparents, Richard Beresford (1761 - 1828) and his wife, Elizabeth (1764-1845).
Samuel Beresford became a successful butcher in the Deer Creek area of Cincinnati an1190d was joined in this profession by four sons: William, Richard, Francis and Samuel Beresford, Jr. and three son-in-laws: Ethan S. Bates, Joseph Whitaker, and Mathew Ryan.

Irish-born Mathew Ryan came to Cincinnati in 1838 with his parents and saw good financial possibilities for himself in the growing meat industry, and he found an entry-level job as a butcher boy with Jonathan King, a prosperous butcher and stockman in the Deer Creek area. His work there brought him in contact with Samuel Beresford and his sons, and through them he met Mary, who became his wife on May 29, 1844.

Two years after their marriage, Mary and Matthew's first child, Samuel was born in 1846, followed by Richard in 1849, Matthew Jr. in 1851 and Elizabeth in 1853. Matthew quickly gained experience in buying, selling, and butchering which soon allowed him to work for himself independently and to become financially successful. Mary's happiness in raising their children was cut short in 1854 when her five-year-old son, Richard, died of scarlet fever. His death greatly affected Mary and Matthew, and soon after they became discontented with Cincinnati and made plans to move elsewhere. In 1856 Mary gave birth to their daughter Katherine.

In 1857 the family moved to Leavenworth, and the following year Mary gave birth to her sixth child, Jeptha, In 1859 their son, Samuel, died of typhoid fever, and two years later their daughter, Elizabeth, died of diphtheria. During the next nine years, Mary gave birth to Alexander, Mary Ann, Thomas and Ethan. When they were baptized, three of her children were sponsored by the Ryan's close friends, Mr. and Mrs. James McGonigle.

While Mary was busy raising their seven remaining children in the family's Catholic faith, and overseeing the daily activities of the household, Matthew's business interests expanded from butcher, to meat processor and packer, to cattle broker. As they grew older, four of the Ryan sons worked with their father on cattle buying trips to Texas, Oregon, and Washington, on cattle drives to Wyoming and Kansas, and operated the family ranches in Montana and Arizona.

After Mathew died in June 1893, Mary remained at their South Esplanade home which she shared for a time with her son, Ethan and his wife and then with her daughter, Mary. In 1909 she moved to New York to live with her daughter there where she died on October 10th. Her body was returned to Leavenworth, and she was buried next to her husband in the Ryan family plot at Mount Calvary Cemetery.

During her lifetime, Mary Beresford Ryan had felt the joy having ten children and saw five of them marry into prominent families. She also knew the sorrow of losing five children prematurely. Through a marriage lasting almost fifty years, she was a major part of her family's triumphs and tragedies. She had been her husband’s enthusiastic supporter and partner and could take equal credit for her family becoming the most prominent cattle men who ever resided in Leavenworth.