Answer:
They develop the idea that, without Congressman Moeller, there would not be a new U.S flag.
Step-by-step explanation:
According to the passage A Flag with 50 Stars, Alaska and Hawaii had been admitted as states, Congressman Moeller had succeeded in having Bob's design chosen as the new U.S. flag.
The two passages develop the idea that, without Congressman Moeller, there would not be a new U.S flag.