The Brooklyn Bridge shows the modernization of America and what it has over come throughout the years. The appearance of the towers itself dates the bridge back to the 1800's without even knowing the background information on the building of it. The actual roadways underneath the walking paths prove that The United States of America has in fact modernized itself throughout the years. This, in it's self, proves that like every country there can become good throughout tragedies. It reviles that the American Dream is limitless. Back in the late 1800's when the building was becoming a starting point of a national monument, it had only been a dream; this dream turned into a greater picture that can be considered the people of this times American Dream. The challenges of this were the lack of now modern day technology, and medicine. The fact that each worker had to go down 150 feet into the ground to remove rock for the foundation to be solid and didn't realize the long term affects of air pressure to the human body was a huge thing to discover (also known as Caisson's Disease). We as humans learned a lot of different things from this construction; like, how the cables had to be twisted together to become stronger. This is proof that if one person has a dream, so do others, and with proper determination anything could become a reality just like the Roebling families own American Dream.
If you wanted more information on this build, a good article source to look at would actually be the Liberty of Congress site for Conservation of the American Memory which is actually a government site as well: http://memory.loc.gov/ammem/today/jun12.html.