I guess it would be because Freedom and Prosperity come hand in hand, like twins, they are almost inseparable, and without Freedom, Prosperity would almost be impossible.
However, in relation to United States History, I don't believe I have any relevant knowledge of that.
People need freedom for their self development and their prosperity in general.
Prosperity
Prosperity is the meaning of sumruddhi.
Freedom for people to choose and to do what is best for them.
unnati
it's meaning is : doing well
For religious freedom and economic prosperity
Means you are rich
prosperity
To bring peace, prosperity, freedom, and security to their nation.
it represents freedom
peace, prosperity and stability