Elizabeth Ellicott Lea was born in Ellicott City, Maryland, the daughter of George Ellicott and Elizabeth Brooke, two of Maryland's leading Quaker families. The Brookes were landowners in Montgomery County; the Ellicott clan, originally from Bucks County, Pennsylvania, settled on land adjacent to the Patapsco River, ten miles west of Baltimore, in 1774. Raising wheat in former tobacco fields, and milling flour at their own gristmill, they soon became the greatest export manufacturers of flour in the area. Their settlement grew into Ellicott City, and the house where Lea was born, built in 1789, still stands as part of the Ellicott City historic district.

Lea's family belonged to the politically and financially important social circles of the day. Her father worked for fairer dealings with Indian tribes, accompanying Gerard T. Hopkins on a Quaker mission to the Indians in Fort Wayne, Indiana, in 1804. Little Turtle and other Indian chiefs visited the family home at Christmas 1807, as recounted by Lea's famous sister, Martha Ellicott Tyson, who wrote of the Ellicott family's history and accomplishments. Martha was a minister in the Society of Friends as well as a founder of Swarthmore College, one of the first co-educational colleges in America. Martha's biography of Benjamin Banneker (1731 - 1806), the African-American scientist and surveyor who recreated Pierre L'Enfant's plans for the new capital of Washington D.C. after the architect quit, is still considered an important historical account. Benjamin Banneker was a friend of Lea and Martha's father, and a colleague of their important uncle, Major Andrew Ellicott, who was surveyor to President Washington. Major Ellicott's brother Joseph, also a surveyor by trade, became Resident-Agent of the Holland Land Company's vast holdings in western New York, and was politically influential in settling the area. Suffice to say, Elizabeth Ellicott Lea was an obscure member of a well-known family.

In 1812, a few weeks before her nineteenth birthday, Lea married Thomas Lea at the Elkridge Friends Meetinghouse on "Quaker Hill" in Ellicott City. Her husband also came from a prominent Quaker family that owned flourmills in Brandywine Village, north of Wilmington, Delaware, and the Leas moved there together after their marriage. Over the following ten years, they began raising seven children, enjoying the large social network of Quakers in the vicinity of Wilmington and Pennsylvania. Living near the shipping centers of Wilmington and Baltimore, the family could obtain foods rarely available elsewhere, such as pineapples, oranges, and winter grapes.

In 1823, the Leas followed cousin Hannah Pierce and her family, who had recently re-settled at Sandy Spring, Maryland on land owned by the Brooke family. The Leas started a farm at Walnut Hill, and Thomas Lea planted an apple orchard that became the most profitable activity on the farm. Life in the remote area was much more difficult than in Delaware, but the two families worked together, building a school for their children and loaning money back and forth. Hannah Pierce reportedly tested many of the recipes Lea would later include in her cookbook. The farmhouse in which Elizabeth Lea lived and did her cooking, and the wall oven in which she did all her baking, are still standing today. Two more children were born before Thomas Lea took ill and died of tuberculosis in 1829. Rebecca Russell, the Quaker nurse who cared for Lea's husband before his death, remained on at Walnut Hill, and became Lea's constant companion. Lea herself became ill late in life, yet she persisted in a project to help young housekeepers by writing a cookbook and domestic manual that would be a simple, straightforward, but complete guide. Russell was her trusted assistant. According to an account from the Baltimore Sun, the invalid Lea would call down recipe instructions from her bedroom to Russell in the kitchen below, where Russell would follow the instructions, and recommend corrections back up to the bedroom.

Lea published her cookbook, Domestic Cookery, Useful Receipts, and Hints to Young Housekeepers in 1845, at her own expense. Unlike other cookbook writers of her day, Lea had no desire to preach scientific cookery, to make her Quaker heritage the focus of her writing, or to compete with literary writers, like Sarah Josepha Hale or Lydia Maria Child, who waxed philosophic in their domestic advice books. Her simple recipes and instructions emphasized economy and self-sufficiency, yet the tone is one of quiet helpfulness, not haughty judgment. Her directions, even to a modern reader, sound easy to follow and at times quite inviting: one may have never made a colored dye for clothing, but the idea of standing in the autumn air, adding peach tree leaves to tint the mixture yellow, does sound appealing. In the "Remarks" section, Lea recommends saving leftovers for the poor and repairing old clothes before giving them away, illustrating the appeal of charity with the borrowed quote, "What I spent I lost, but what I gave away remains with me."

Lea lived to see one daughter and two sons marry, one child die young. The remaining five were unmarried. Her son-in-law's father, Edward Stabler, was a Quaker leader of the Temperance movement and a druggist who could claim George Washington as a customer. As culinary historian William Weaver points out, it is likely that many of Lea's herbal remedies can be traced back to Stabler. Lea's illness (the nature of which is unclear) was incurable, and she died on December 30, 1858 at age sixty-five. The January 15, 1859 Friends' Intelligencer published an obituary praising her patience with illness, her concern for the poor, and her strong faith, but made no mention of her cookbook. Lea had revised Domestic Cookery in 1846 and 1851, enlarging the work with each revision. The 1851 edition became the standard, reprinted until the book went out of print in 1879, after nineteen editions.

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