Also known as Dot or Dottie, Parker was born Dorothy Rothschild in 1893 to Jacob Henry Rothschild and his wife Eliza Annie (née Marston) (1851–1898) at 732 Ocean Avenue in Long Branch, New Jersey. Her parents had a summer beach cottage there. Parker's mother was of Scottish descent. Her father was the son of Sampson Jacob Rothschild (1818–1899) and Mary Greissman (b. 1824), both Prussian-born Jews. Sampson Jacob Rothschild was a merchant who immigrated to the USA around 1846, settling in Monroe County, Alabama. Jacob Henry Rothschild was one of five known siblings. The others were: Simon (1854–1908); Samuel (b. 1857); Hannah (1860–1911), later Mrs. William Henry Theobald; and the youngest, Martin Rothschild, born in Manhattan on December 12, 1865, who perished in the sinking of the Titanic. Parker wrote in her essay, "My Hometown," that her parents returned to their Manhattan apartment shortly after Labor Day so that she could be called a true New Yorker. Her mother died in Manhattan in July 1898, a month before Parker's fifth birthday.