Steel is one of the most easily and extensively recycled materials on earth:
There are two ways to make steel: one is to create virgin steel from iron ore and coke, and the other is to melt down used steel and recycle it. Recycled steel is just as strong as virgin steel. Unlike paper and plastic, steel can be melted down and recast indefinitely; it has no structural memory. Making recycled steel, in electric-arc furnaces, or E.A.F.s, requires less capital investment than making virgin steel, which is manufactured in huge integrated mills; it also saves energy, and is easier on the environment, because not so much ore has to be mined. The only disadvantage of recycling is that it can be hard to know exactly what's in your raw material -- the steelamker must rely on the scrap dealer's ability to separate out other metals, particularly copper, which can weaken the steel. In 2006, two out of every three tons of steel made in the U.S. came from recycled steel.
That's from John Seabrook's recent article on the scrap metal industry for The New Yorker (not online).
Steel production began far earlier than is commonly known...around 1400 BC in East Africa. Steel was also produced in China, India, Spain/Portugal, and other places before 1000 AD. The Bessemer Process was the first inexpensive industrial process for mass-producing high quality steel; that was in the 1850s.
In 1901, J.P. Morgan founded US Steel, which at one point made 67 percent of all steel produced in the US and was part of the Dow Jones Industrial Average from 1901 to 1991. US Steel was once the largest corporation in the world, a title now held by (depending on how you define "largest") Wal-Mart, a company that sells fewer and fewer things made of steel, or PetroChina with its $1 trillion market cap. It's too bad oil can't be effectively recycled after use; it's a stretch to think of elevating our atmosphere's carbon dioxide levels for the purpose of warming some parts of the world as recycling.