​The 1814 burning of Washington, D.C.

Two centuries ago this past week, smoke and ash lingered in the air of what remained of our nation's capital. Mo Rocca takes us back to that fiery night:

Two hundred years ago this month, 4,000 British soldiers lay siege to Washington, D.C., and set fire to the U.S. Capitol and the White House.

A drawing of the White House after the fire of 1814. Library of Congress

And the burn marks on the White House walls are still there.

"We now have evidence of the char marks, the scorching that would have happened when flames were drawn out through open windows and doors and licked up around the tops of the stone," said William Allman, the White House curator.

It is, as far as we know, the best evidence the one time enemy's forces were in our nation's capital, said Allman.

The burning of Washington was the darkest moment for the United States and President James Madison in the War of 1812 -- a sort of second war of American independence.

The British had been interfering with American trade at sea and kidnapping sailors. American efforts to expand westward and north into Canada were being thwarted by the British. Two years into the war, with the Americans in retreat, British forces reached the nation's capital.

Rocca asked, "What was Washington like in 1814?"

"Miserable," said William Allen, historian emeritus for the Architect of the Capitol. "Tiny, small, strung out."

200 year later, the White House still bears the burn marks of the fire. CBS News

It was basically, he said, a construction site: "There were stone yards and brick yards and kilns. It was just a mishmash of this and that."

The Capitol dome hadn't yet been built, but the original House chamber -- located on the site of today's Statuary Hall -- was an architectural masterpiece.

"Many people described it as the most beautiful room in America," said Allen. "It had this glorious ceiling with 100 skylights."

Allen said the room was fireproof, except for the ceiling. "And that, of course, was the Achilles' heel of the room. The ceiling was wooden, and all they had to do, of course, is to catch the ceiling on fire. When it fell down, the rest of the room would be destroyed.

"The heat was intense. The glass in the skylights melted, became molten, and fell down in large chunks."

The Capitol's stone walls survived, as well as the Senate vestibule, with its distinctive corn cob columns.

Allen said the corn cob was significant as "the American plant, in a classical way. Sort of thinking the way classical architects would have thought, using this very important staple of the American diet and the American economy."

Fighting with the British that night were former American slaves:

"The British brilliantly exposed a real weak side in American society, and that was slavery and our dependence on slaves," said historian Steve Vogel, author of "Through the Perilous Fight," a blow-by-blow account of Washington's capture. "They offered freedom to slaves in this region, the Chesapeake. Said, you know, 'Come over to our side. We promise you freedom. And if you want to, by the way, you can fight against your former masters.'"