There are unsettling ghosts of America past all about the National Mall. Hundreds of thousands of people will gather there Tuesday for the inauguration of the nation's first African-American president. Three blocks from where Barack Obama takes the oath, there was once the Saint Charles Hotel, a popular accommodation on Pennsylvania Avenue before emancipation ruined business for slave traders. It proudly advertised that down below its first-rate restaurant, guests could avail themselves of six, 30-foot-long arched slave cells, replete with wall rings and shackles. The management promised: ''In case of escape, full value for the Negro will be paid.'' A few blocks from there was the notorious Yellow House, a three-story brick slave market where trader William Williams prospered enough to purchase two slave ships of his own. Solomon Northrup, a free man from New York who was kidnapped into slavery, passed through on the block and eventually wrote a memoir. He recalled how ''the voices of patriotic representatives boasting of freedom and equality,'' in the nearby Capitol almost commingled with ''the rattling of the poor slave's chains.'' [ABSTRACT FROM PUBLISHER]