Ellen Louise Curtis was born on November 15, 1824. While her early life is not extensively documented, her upbringing likely instilled in her the skills and resourcefulness that would later define her entrepreneurial endeavors.

In the 1850s, Ellen Louise Curtis began her career as a milliner in New York City. This experience provided her with valuable insight into the fashion industry, including current styles, consumer demand, and the challenges of creating fashionable garments.

Ellen Louise Curtis married William Jennings Demorest, a man with a strong business sense and radical social ideas. Their partnership would be crucial in establishing and expanding their business ventures.

The year 1860 marked a turning point with the invention of mass-produced, graded tissue-paper dressmaking patterns. This innovation allowed women to easily create fashionable clothing at home, democratizing fashion and significantly reducing the cost compared to purchasing custom-made garments. This was a crucial step as this gave women more independence and confidence.

Ellen and William Demorest opened 'Demorest's Emporium of Fashion' in New York City. This establishment not only sold paper patterns, but also offered a variety of other fashion-related goods and services, becoming a hub for style-conscious consumers.

In 1864, the Demorests launched 'Demorest's Illustrated Magazine', a publication dedicated to fashion, home decor, and literature. The magazine featured their dressmaking patterns, further promoting their brand and providing fashion advice and cultural commentary to a wide audience. It was more than just a fashion magazine; it also reflected the Demorests' progressive views on women's rights and social reform.

The Demorest business continued to thrive throughout the 1870s and 1880s. Their patterns and magazine became increasingly popular, and they expanded their operations, opening branch stores and agencies across the United States and internationally. Their innovative approach to business and their commitment to fashion accessibility made them leaders in the industry.

Ellen Louise Demorest passed away on August 10, 1898. By this time she had cemented her legacy as a pioneer in the fashion industry and a businesswoman who helped shape the landscape of consumer culture in America. Her patterns, magazines, and entrepreneurial spirit had a lasting impact on the lives of women and the development of the fashion industry.