In 2012, U.S. farms sold nearly $395 billion in agricultural products.
Agriculture is a major industry in the United States, which is a net exporter of food. As of the 2007 census of agriculture, there were 2.2 million farms, covering an area of 922 million acres (3,730,000 km 2), an average of 418 acres (1.69 km 2) per farm. Between 1930 and 1942, the United States' share of world soybean production skyrocketed from 3% to 46.5%, and by 1969 it had risen to 76%. By 1973 soybeans were the United States' number one cash crop, and leading export commodity, ahead of both wheat and corn. In 2012, U.S. farms sold nearly $395 billion in agricultural products. This was $97 billion, or 33 percent, more than in 2007, at the time of the last agriculture census. Crops accounted for $69 billion of the increase, and livestock accounted for $29 billion. Compared to 2007, crop sales were 48 percent higher and livestock sales were up 19 percent. (Table 1) Crops accounted for 54 percent of agriculture sales in 2012. Five years earlier they accounted for just under half of sales. In contrast, less than half of one percent of farms had agriculture sales of more than $5 million, but these few farms produced 32 percent of the total value of all agricultural products sold. Farms with sales of $1 million or more 4 percent of all farms produced 66 percent of the total value. (Fig. 1 Cash receipts for Colorado livestock and products total more than $3.7 billion, of which more than 75 percent of cash receipts come from cattle and calves. 2  Of Colorado’s $3.7 billion livestock industry, 75 percent comes from cattle and calves. Colorado Beef Industry Facts. 1  The U.S. now imports about 54 percent of its oil; by the year 2015, that import figure is expected to rise to 100 percent. -- THIRSTY PRODUCTION SYSTEMS. U.S. agriculture accounts for 87 percent of all the fresh water consumed each year. Livestock directly use only 1.3 percent of that water. But when the water required for forage and grain production is included, livestock's water usage rises dramatically. Every kilogram of beef produced takes 100,000 liters of water. Other ratios range from 13:1 for turkey meat and 14:1 for milk protein to 17:1 for pork and 26:1 for eggs.). Animal agriculture is a leading consumer of water resources in the United States, Pimentel noted. Grain-fed beef production takes 100,000 liters of water for every kilogram of food. In 1870, 70-80 percent of the US population was employed in agriculture. As of 2008, less than 2 percent of the population is directly employed in agriculture. In 2012, there were 3.2 million farmers, ranchers and other agricultural managers and an estimated 757,900 agricultural workers were legally employed in the US. Between 1930 and 1942, the United States' share of world soybean production skyrocketed from 3% to 46.5%, and by 1969 it had risen to 76%. By 1973 soybeans were the United States' number one cash crop, and leading export commodity, ahead of both wheat and corn. Chicken meat production consumes energy in a 4:1 ratio to protein output; beef cattle production requires an energy input to protein output ratio of 54:1. (Lamb meat production is nearly as inefficient at 50:1, according to the ecologist's analysis of U.S. Department of Agriculture statistics. Other ratios range from 13:1 for turkey meat and 14:1 for milk protein to 17:1 for pork and 26:1 for eggs.). Animal agriculture is a leading consumer of water resources in the United States, Pimentel noted. Grain-fed beef production takes 100,000 liters of water for every kilogram of food. Corn-based ethanol production in the United States has plateaued in recent years. Corn is the major agricultural input used in the United States to produce ethanol, accounting for 35-40 percent of U.S. corn use in recent years. Rapid expansion of ethanol production in the past decade reflects a response to high crude oil prices, the Renewable Fuel Standard, and other factors. Crops account for the largest share of the value of U.S. agricultural production. The value of agricultural production in the United States rose over most of the last decade due to increases in production as well as higher prices. U.S. agricultural production occurs in each of the 50 States. In terms of sales value, California leads the country as the largest producer of agricultural products (crops and livestock), accounting for almost 11 percent of the national total, based on the 2012 Census of Agriculture. Crops account for the largest share of the value of U.S. agricultural production. The value of agricultural production in the United States rose over most of the last decade due to increases in production as well as higher prices. The value of production for cattle and calves was roughly $45.2 billion. In addition, the value of milk production was about $39.7 billion, 26.0 percent higher than in 2010. The poultry industries were the next largest commodity in the United States, with production valued at around $35.6 billion. 
https://en.wikipedia.org/wiki/Agriculture_in_the_United_States http://www.agcensus.usda.gov/Publications/2012/Online_Resources/Highlights/Farm_Economics/ https://www.colorado.gov/pacific/agmarkets/livestock-0 http://news.cornell.edu/stories/1997/08/us-could-feed-800-million-people-grain-livestock-eat https://en.wikipedia.org/wiki/Agriculture_in_the_United_States http://news.cornell.edu/stories/1997/08/us-could-feed-800-million-people-grain-livestock-eat http://ers.usda.gov/data-products/ag-and-food-statistics-charting-the-essentials/agricultural-production-and-prices.aspx http://ers.usda.gov/data-products/ag-and-food-statistics-charting-the-essentials/agricultural-production-and-prices.aspx http://www.aphis.usda.gov/animal_health/nahms/downloads/Demographics2011.pdf
what percentage of agriculture in us is livestock production