William levitt was able to create affordable homes in postwar america by

Lowering cost of building by making his own wood and nails and broke down construction process into 27 separate tasks and assigned each task to a group of workers who would go from house to house repeating their specific task at each building site. He would also have truck drop off what ever they needed right where they needed them and make people who clean the house, add flooring/tiles/painters/etc in in turn for each house to make it go faster 

Because it involves various stages and personnel and often does not get a bill passed.

Explanation:

The United States legislature was purposely designed to be slower in taking action. This is because the founding fathers wanted to prevent the infringement of citizens' rights and freedoms.

Thereby, the legislature involves various personnel and stages before bills and laws are passed. Also the legislature is bicameral in nature as it requires the passing of House and Senate through debates and votings.