In 1969, the number of US troops in Vietnam was around 500,000. This figure is based on historical data regarding the Vietnam War.
To arrive at the correct answer, let's consider the multiple choice options provided:
1. 50,000
2. 100,000
3. 500,000
4. 1,000,000
Given the options, the accurate number of US troops in Vietnam by 1969 is 500,000. Therefore, the correct answer is:
500,000
