WASHINGTON (AP) — Millions of people worldwide are held in modern slavery and sex trafficking, and experts say that's more than at the height of the trans-Atlantic slave trade.So, President Abraham Lincoln's Cottage, a house museum in Washington, is tackling the issue of modern slavery in the place where Lincoln drafted the Emancipation Proclamation.An exhibit opening Friday tells stories of women working as domestic servants without pay, of women forced into prostitution and of men held in servitude through debt contracts. The exhibit, "Can You Walk Away?" marks the 150th anniversary of the Emancipation Proclamation and is on view through August 2013.Museum Director Erin Carlson Mast says many people believe slavery was resolved after the Civil War and don't realize it's a growing problem.