Early in January 1844, six Sisters of Notre Dame de Namur (SNDdeN) departed Antwerp aboard L'Infatigable bound for the Oregon Country. After a long journey that took them around the tip of South America, they crossed the treacherous Columbia River bar on July 31. Accompanied by their recruiter, Rocky Mountain Jesuit missionary Pierre Jean DeSmet, the Sisters and four other Catholic priests constituted a significant reinforcement for the recently established Catholic missions in the Pacific Northwest. The Oregon mission was the second North American foundation for the Sisters, after Cincinnati, Ohio (1840). They were the first Catholic nuns in the Pacific Northwest.

Founded in Amiens, France, in 1804 by Saint Julie Billiart and François Blin de Bourdon, the Sisters of Notre Dame de Namur dedicated themselves to the education of girls, especially the poor, and to training teachers. Their educational mission, originally designed to help reestablish Catholicism in post-revolutionary France, broadened to include the general education of all classes of girls as demand for more formal training increased throughout the nineteenth century. Unresolvable differences with ecclesiastical authorities in Amiens led to the abandonment of their French establishments in 1813 and the transfer of the Sisters’ headquarters to Belgium, with the motherhouse at Namur.

In Oregon, the Sisters established their first school at St. Paul (in present-day Marion County)—Sainte Marie de Willamette (later officially chartered as St. Paul’s Mission Female Seminary). The school primarily attracted the daughters of the Canadian fur traders and Native American or women of mixed ancestry who settled at French Prairie (between the Willamette and Pudding Rivers north of Salem). The Sisters also prepared local Indian women and fur trader's wives to receive the sacraments. A farm supported the community with foodstuffs for their own consumption and products to sell and served as a training ground for its students who worked in the fields and learned to produce marketable goods. The nuns offered instruction in French and also acquired some knowledge of the Chinook Jargon familiar to their students.

Following the arrival of an additional seven Sisters from Belgium in 1848, a second school—the Young Ladies’ Academy at Oregon City —catered to families in the upper ranks of the fur trade and to incoming American and European settlers.  Students included the granddaughters of John McLoughlin and daughters of several well known Oregon pioneers. The Oregon City school followed a more refined curriculum taught in English.

American settlement brought with it the anti-Catholicism rampant in the States, further encouraged by Protestant missionaries in Oregon. Tensions following the murder of the Whitmans at Waiilaptu, the population drain caused by the California gold rush, and an epidemic of diseases among the part-native students strained the Sisters’ nerves and resources. The Sisters closed the St. Paul school in 1852. In the following year, they shuttered the Oregon City academy, sold their Oregon properties, and transferred all goods, personnel, and a few remaining students, to San José, California. Their Willamette Valley religious associates, the Jesuits, had already relocated to neighboring Santa Clara.  To this day, the Sisters of Notre Dame de Namur maintain an active educational mission in California.