To ensure that Joe's sample of 10,000 adults is representative of the population and avoids bias, he should aim to select the same number of individuals from each state. Since there are 50 states, he can divide the total sample size of 10,000 by the number of states:
\[ \text{Number of people from each state} = \frac{10,000 \text{ adults}}{50 \text{ states}} = 200 \text{ adults per state} \]
Therefore, Joe should choose 200 adults from each state.