Chart of american indian, inuit and aleut population by U.S. State (1890-2010)

The census counted 248,000 Indians in 1890, 332,000 in 1930 and 334,000 in 1940, including those on and off reservations in the 48 states. Total spending on Indians averaged  $ 38 million a year in the late 1920s, dropping to a low of  $ 23 million in 1933, and returning to  $ 38 million in 1940.

Reference 1: United States, Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming and Puerto Rico.

Reference 2: 1890, 1900, 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, 2000 and 2010.

Source: http://en.wikipedia.org/wiki/Indigenous_peoples_in_the_United_States