What meant that the dollar was convertible into gold only?

What is the value of a 1920 cent? A court-devised doctrine that if it is nessary to restrict the rights of one person to speak or publish in order to protect the rights of another? Name of Abraham Lincoln's horse? Who was a former slave who escaped and became a abolitionist? Why was Lincoln's inauguration in 1861 more like a funeral than a victory celebration? Who was the only president married in the whitehouse? How did the light bulb change America? What is the Alpha phi alpha prayer? Was Eli Whitney a lady? why although the women right movement led to many advances women in the united states continue to struggle to secure? John Locke and Jean Jacques Rousseau would be most likely to support? Who were the ten richest American colonial families? What was the names of Edward Thomas' children? How did the Indians get to north America? What are some of the main questionw people asked about Cuba during the Spanish American War? Where can you get a banner made? What is pro-slavery ideology? How did the north try to avoid the civil war? What is the value of a 1904 O Liberty Head Silver Dollar worth? In what order did mesoamerican civilizations arise?

What meant that the dollar was convertible into gold only?