This article is part of a recurring series on Wall Street's storied past. All events presented here took place on one or more of the years following the 1896 creation of the Dow Jones Industrial Index.

The modern American military-industrial complex took clearer shape on this day 71 years ago as citizens of the United States felt themselves pulled toward a seemingly inevitable war.

Ground was first broken in the construction of the Pentagon on Sept. 11, 1941. It would be completed in early 1943 at a cost of $83 million. As of this year, the Pentagon became the control center of a government agency with a $530 billion annual budget.

President Franklin Delano Roosevelt used his fireside chat on Sept. 11, 1941 to publicly announce that the Navy would thereafter attack Axis ships on sight:

When you see a rattlesnake poised to strike, you do not wait until he has struck before you crush him. These Nazi submarines and raiders are the rattlesnakes of the Atlantic. They are a menace to the free pathways of the high seas. They are a challenge to our sovereignty. They hammer at our most precious rights when they attack ships of the American flag -- symbols of our independence, our freedom, our very life.

From now on, if German or Italian vessels of war enter the waters, the protection of which is necessary for American defense they do so at their own peril. The orders which I have given as Commander in Chief of the United States Army and Navy are to carry out that policy -- at once.

The Dow Jones Industrial Average (INDEX: ^DJI) closed on this day in 1941 at 127.15. Anyone investing in the Dow at that time would have earned a 6.8% annualized rate of return, not including any reinvested dividends, to the present day.

Two companies on the index in 1941 would be most closely associated with wartime production: Bethlehem Steel, owner and operator of multiple major shipyards, and United Aircraft. Bethlehem Steel filed for bankruptcy in 2001, and its assets sold to the International Steel Group in 2003. International Steel Group's assets are now part of ArcelorMittal (NYSE: MT). United Aircraft became United Technologies (NYSE: UTX) in 1974 and remains part of the Dow today. Buying United Technologies and holding its stock from 1941 onward would have produced a 10% annualized rate of return to the present day -- not counting any reinvested dividends.

Four companies, including United Technologies, have maintained their place in the Dow without being acquired or undergoing major corporate restructuring since 1941. The other three are DuPont, General Electric (NYSE: GE), and Procter & Gamble (NYSE: PG). GE and Procter & Gamble today each have larger individual market caps than the 1941 GDP of the U.S.

United Aircraft saw enormous benefits from its wartime contracts, which dwarfed those of other aircraft manufacturers. Find out which companies might be today's federal-funding winners in the Fool's free report: "Stocks That Could Skyrocket After the 2012 Presidential Election."