The Smith College Relief Unit was founded in 1917 by Harriet Boyd Hawes (1892) to bring relief to those areas of France that were most devastated during the first World War. Hawes already had significant experience of relief work when she proposed, at a Boston Smith Club meeting in 1917, to form the SCRU. She had served as a relief nurse in both the Greco-Turkish war of 1897 and the Spanish American war, and then later in France, when WWI began. Having seen first-hand the effects of the war in Europe, Hawes was dismayed at the apathy expressed towards it by Americans when she returned to the States. When the US finally did join the war, Hawes quickly announced her intentions of starting a relief unit, which she hoped to staff with other Smith graduates. Smith alumnae were eager to lend their services; a Committee of Five was established to manage business in the US, and the necessary money was soon raised. The group attained the recognition of the State Department early on, and an affiliation was established with the American Fund for French Wounded through Harriet's previous connections in France. By 1918, after the Unit had proven its success, the Red Cross accepted the SCRU as an affiliate as well, granting the Unit another source of aid and support.

That summer, with a pledge of $30,000 from alumnae, Hawes set off with seventeen other Smith graduates for France. Their base was to be in the village of Grecourt in the devastated Somme Valley, chosen by the French government as the area of greatest need. When they arrived in Grecourt, the women of the Unit found that not a single building had been left intact; the Germans bombed everything before they left and deported all the able-bodied youth, leaving only the old and the sick and those children who were too young to work. Any machinery that might have been a help to the villagers had been broken, and once-fertile fields were unrecognizable. The primary interest of the Unit was in helping the villagers to regain self-sufficiency. As much as was possible the Unit bought from the villagers food for themselves and fodder for their livestock, much of which was sold back to the villagers at well below original cost. A store was established from which basic staples and supplies were sold. The Unit also kept a truck which they used as a "traveling store." The SCRU rebuilt St. Matthew's Church and revived services by bringing a minister to the town. They built a school, a library and hospital, planted fruit trees, wheat and vegetables and provided medical services. Sewing was given out to the local women, for which the women were paid according to scales established by the French government. The SCRU taught classes to children, including carpentry, sewing, cooking, music, games and physical education, along with a curriculum of reading and arithmetic.

In March of 1918 a new German offensive forced the evacuation of Grecourt and the surrounding villages. The Unit relocated for a time in Beauvais, where the members worked with the Red Cross to treat the American wounded. Many of the volunteers, having finished their required terms, and having seen more of battle than they bargained for, returned to the States. Among these was Hannah Dunlop Andrews, the director of the Unit, who felt she must give up her position in order to return home with her husband, a Major in the American Army. When the war ended, a new director, Marie Wolfs, was appointed and the Unit returned to Grecourt. The village was even more devastated than at the time of their first arrival, and much of their work had been lost.

The Red Cross began to disband their relief services that November, and the SCRU was an independent organization again. Those who stayed on at Grecourt did so at the request of the French government and out of a sense of commitment to and investment in the project. The last of the Unit's members did not leave France until 1929, by which time they had rebuilt and improved upon all that was lost in the German strike of 1918. The Smith College Relief Unit was the first college women's unit in France and the first to be acknowledged by the Red Cross. Inspired by the Smith Unit, several other colleges followed, including Wellesley and Bryn Mawr.

Though by all accounts those who served in the Smith College Relief Unit would never see fit to mention it, certain tangible rewards were given to commemorate Unit's work. In 1919 the Union des Femmes de France (a French branch of the Red Cross) awarded the women the Medaille de Guerre in recognition of their work in the evacuation of March 1918, and in 1920 the French government awarded the Unit the silver medal of Reconnaissance. The Croix de Guerre was awarded to those villages that the Unit served, for bravery under German occupation, and at Smith, the Grecourt Gates, a replica of those that stood in front of the Chateau de Robecourt, were erected by the Trustees of the College in front of College Hall.