Midwestern pioneers brought from Nebraska and Iowa by Dos Palos founder Bernhard Marks were the first to settle the area over 100 years ago.
In the 1900's cattle baron Henry Miller sought Italians from Gramento Nova and Sicily to work the area ranches, railroads and stores, particularly in the South Dos Palos area.
From 1915 to 1925, Azorean Portuguese arrived to farm and mill rice in the South Dos Palos area and on the Westside plains.
As cotton was planted and became the area's premiere crop, many African-Americans from the South, primarily Texas, Arkansas, and Oklahoma came to work the fields.
During the World War II years, Eagle Field, a nearby Army Air Crops training base was established. After the war, many cadets returned to settle in Dos Palos--some to marry their girlfriends.
The late 1950's saw many farmhands and their families come from Oklahoma and some from Arkansas and Texas.
With the lifting of quotas and in relief from volcanic eruptions and earthquakes, more Azorean Portuguese immigrants arrived in the early 1960's and 1970's.
The late 1970's and 1980's saw emigration from the area due to the splitting of the high school district with the neighboring town of Firebaugh, the closure of a large textile mill (Tubbs Cordage), a widespread agricultural depression and the completion of Interstate 5 (replacing Highway 33 as the Westside highway).
The 1990's have generally been growth years with many former residents of Dos Palos returning to raise families, also some commuters relocating from the San Jose area or coastal towns.