The 20th century ushered in a change from handcrafting to machine tooling. Henry Ford introduced one of the first moving assembly lines as a way to turn out more cars more quickly, and the emerging auto industry popularized this mode. A photo of the Doble Steam Motors Corporation factory shows a line of workers and car chassis in production. This new technology, and the spread of industrialization, changed forever the way that work was completed. A wide variety of industries all across the country converted to mechanization, and California was no exception. One 1929 image shows young women working in a towel factory in Orange. Photographs taken in San Francisco illustrate that workers used machines to make products as different as Ghirardelli Chocolate and music rolls for automated player pianos. Images also show women working on an assembly line in a soap factory, and men sewing clothes in a shop (at a time when a good suit, cut on machines instead of by hand, retailed for $40 to $50). Automation and mechanization also changed agricultural practices. The combined traction steam harvester built by Stockton J. Barry on his California ranch was one of the machines that changed the way produce was harvested. Mechanized canning changed the way fruit and vegetables were processed and preserved, and made out-of-season produce available year round. Photographs in this group show cannery workers at tables, and cans going through a labeling machine. The introduction of mechanized food processing eventually brought a new awareness of the importance of standards for foods production. The Pure Food and Drug Act and the Meat Inspection Act were both passed in 1906. As workers nationwide adjusted to an increasingly mechanized workplace, good working conditions took on new importance. Workers in several industries formed unions (such as the Berryessa Fruit Growers formed in 1920, shown here) to promote safer working conditions and limit maximum working hours.

In 1931, a severe drought hit the Southern and Midwestern plains. As crops died and winds picked up, dust storms began. As the "Dust Bowl" photograph shows, crops literally blew away in "black blizzards" as years of poor farming practices and over-cultivation combined with the lack of rain. By 1934, 75% of the United States was severely affected by this terrible drought.The one-two punch of economic depression and bad weather put many farmers out of business. In the early 1930s, thousands of Dust Bowl refugees ? mainly from Oklahoma, Texas, Colorado, Kansas, and New Mexico ? packed up their families and migrated west, hoping to find work. Entire families migrated together (such as the men shown in "Three generations of Texans now Drought Refugees") in search of a better life. Images such as "Midcontinent ? Family Standing on the Road with Car," "Drought Refugees," and "Untitled, ca. 1935 (Worn-Down Family in Front of Tent)" offer a glimpse into their experience on the road, and show that cars provided many families both transportation and shelter on the road. About 200,000 of the migrants headed for California. The state needed to figure out how to absorb the thousands of destitute people crossing its borders daily. One of their tactics was to document the plight of the refugees. In 1935, photographer Dorothea Lange joined the Rural Rehabilitation Division of the California State Emergency Relief Administration (SERA), a section of the Federal Emergency Relief Administration. She was assigned the job of using her camera to document the growing number of homeless Dust Bowl refugees migrating to California. She worked with Paul S. Taylor, a professor at the University of California, Berkeley, who was researching conditions of rural poverty in order to make recommendations on how to improve the workers' conditions. The work by Taylor and Lange played an important role in helping to raise public awareness of the crisis. The reports they made for the government included both data and striking images that revealed the desperate conditions in which the migrants lived and confirmed the need for government intervention. Stark images such as "Home of Oklahoma Drought Refugees" resonated with the public, and portraits of drought refugees like "Ruby from Arkansas" and others shown in this topic humanized the migrants for more fortunate citizens. In March 1936, Lange took what became one of her most famous images, "Migrant Mother." This image of a 32-year-old woman became an icon for the suffering of ordinary people during Great Depression.

In 1862, Congress passed and President Lincoln signed the Pacific Railroad Bill, which granted public land and funds to build a transcontinental railroad. The Central Pacific Railroad would lay tracks from California heading east, and the Union Pacific Railroad would lay tracks from the Missouri River west. The photograph taken in Placer County, "Grading the Central Pacific Railroad," shows some of the construction. Work on the railroad was physically difficult and at times dangerous, and attracting workers was a challenge. The majority of the Central Pacific's laborers were Chinese. A Chinese worker is shown in the image "Heading (top cut) of East Portal, Tunnel No. 8." Both railroad companies actively recruited Chinese laborers because they were regarded as hard workers and were willing to accept a lower wage than white workers, mostly Irish immigrants. As construction progressed, the Central Pacific and the Union Pacific competed to see which could lay the most track each day. A photograph of a sign near Promontory Park, Utah, commemorates the day that Central Pacific crews laid an unprecedented 10 miles of track. The meeting of the two sets of tracks ? the "gold spike" ceremony ? took place on May 10, 1869. Several photographs and drawings depict this historic moment. Now the country was connected as never before: a journey between San Francisco and New York that previously took up to six months now took only days. The photograph "High Bridge in Loop," from Views from a Trip to California, shows a train passing quickly through a mountain pass. The transcontinental railroad allowed people to travel more, farther, and in pleasant conditions, as reflected in the photograph "Commissary Car, 'Elkhorn Club.'" The photograph "Knights of Pythias at the Santa Fe Railway Station, Anaheim" shows an example of the popularity of trains. Even as the transcontinental railroad brought the new country together, it brought change to the world of Native Americans. The tracks ran through a number of tribal territories, bringing into conflict cultures that held very different views of the land and how it might be used and lived on. The painting The First Train, by Herbert Schuyler, depicts three Indians pointing past their encampment at a train in the far distance. The railroad also brought an increasing number of European Americans west. One consequence of this influx was the depletion of the buffalo herds, a major food source for Plains Indians. European Americans would often shoot buffalo for sport from the train; by 1880, the buffalo were mostly gone and Plains Indians had been gathered onto reservations. Millions of acres of open grassland were being settled by the people moving west. Eventually, much of this land became the farmland that fed a growing nation. The transcontinental railroad opened up the West to the rest of the country, even if they never made the trip themselves. A Currier & Ives hand-colored lithograph depicts a train running along the Truckee River in Northern California. The San Francisco publishing firm of Lawrence & Houseworth hired photographers and published photographic tourist catalogs containing views of the West, which they sold commercially. The railroad took hold in popular culture, as shown by sheet music for the song "New Express Galop [sic]." There was even a railroad board game illustrating "Railroads Between New York and San Francisco, California, with Scenes on the Way."