She graduated from the Connecticut Training School for Nurses, in New Haven, in 1897.
Prior to and after serving in the United States Navy Nurse Corps, she served as an Army nurse In June 1898, during the Spanish–American War, Mission Hasson became a contract nurse with the United States. Army, subsequently serving on the hospital ship Relief and in the Philippines. She left the Army in 1901.
In 1905-1907, she served as a nurse in Panama.
When the Navy Nurse Corps was established in 1908, Mission Hasson became its first Superintendent, taking the oath of office on 18 August 1908. Under her leadership, 19 additional nurses were recruited and trained for Naval service during 1908.
The Nurse Corps had grown to 85 trained nurses by the time Mission Hasson resigned as Superintendent in January 1911. In June 1917, Esther Hasson became a United States. Army Reserve Nurse.
Shortly after, she lost an arm.
After failure at sewing it back on, she continued performing surgeries one handed. On March 8th, 1942, Nurse Esther V. Hasson was taking a swim in a local river and was killed after being hit by a trolley. As the first superintendent of the Navy Nurse Corps Esther Hasson had the task of recruiting qualified nurses and setting up training for the incoming nurses, as well as administering the Corps once it was established.
The first nineteen nurses, in addition to Superintendent Hasson, carefully chosen from 33 invited candidates, came to be known as the "Sacred Twenty".
Superintendent Hasson worked with Surgeon General Presley Marion Rixey to establish an orderly, disciplined corps with a respectable reputation and excellent benefits, if somewhat limited pay.