For a long time, the west coast region of the United States was seen as a colony of the eastern part, but this area developed greatly under the New Deal. Large federal fiscal expenditure promoted water resource development under the Reclamation Act, and established key infrastructure for the post Second World War era in California's Central Valley. First, this paper analyzes the process and accomplishments of the Central Valley Project (CVP), an important irrigation project in the California Central Valley area. The CVP still plays an important role in irrigation water development in the State of California, home to the largest area of agricultural land under irrigation in the United States. Two vital factors in the realization of the CVP were continuous lobbying by farmers, agribusinesses and landowners in the area, and federal government spending policy in the New Deal era. One of the conditions for securing federal funding was that the project should be operated such that the benefits of development of the CVP were distributed as widely as possible. However, large landowners strongly opposed this form of ideal operation and under the Reclamation Act successfully had it reversed, eventually converting the CVP into their personal means of capital accumulation. Second, this paper reveals that interested parties in the Central Valley, such as large landowners, lobbied actively for the Bracero Program. For this reason, Mexican agricultural labor was introduced into the Central Valley. This means that large landowners received Federal funding, and furthermore, large landowners worked with the Farm Placement Service of California State Department of Employment to set the wages of agricultural labor at a very low level. Gradually, American workers were excluded from the agricultural labor market in California. Since the Bracero Program severely limited labor movement in the Central Valley, agricultural working conditions were left in a poor state. Initially, the United States Bureau of Reclamation had intended that Americans from the eastern part of the United States would be the new residents in the reclamation project area but instead Mexicans began to reside in Central Valley. While some of the United States' leading rich farmland was formed in the Central Valley, some of the worst poverty areas also appeared there. In the Central Valley area, such New Deal economic policies were seriously frustrated after the Truman administration. In the end, due to powerful lobbying, two federal policies in the State of California greatly contributed to the development of commercial agriculture in the Central Valley.