September 7 is Labor Day in the U.S., a national holiday that began more than 100 years ago to honor low-paid factory workers. Labor Day also informally marks the end of summer. Many children return to school after Labor Day, and the warm days of summer turn cooler. Many Americans celebrate the holiday with one last family meal outdoors. But Labor Day started with a struggle. On May 1, 1889, workers demonstrated on the streets of Paris. International Labor Day was born. Most industrialized countries in the world -- except the U.S. and Canada -- celebrate Labor Day on the first of May. The first American Labor Day celebration was held in New York City on September 5, 1882. About 10,000 workers marched through the streets to show the strength of labor organizations. For many years after that, American workers used the first Monday in September to demand better working conditions and pay. Music was part of many of those marches.Labor songs traditionally tell stories of conflict and hopes for a better life. Here is Pete Seeger's "We Shall Not Be Moved." Many classic American labor songs came from workers in the coal mines of the South. Mine owners bitterly opposed workers' unions. In Kentucky, company police searched for union leaders. They waited outside a worker's home for several days to block him from organizing. The coal miner's wife, Florence Reece, stayed inside with her children. She wrote this song, "Which Side Are You On?" And again, here is Pete Seeger. Another American labor song is called "Bread and Roses." It is based on a poem by James Oppenheim, published in December 1911. The poem speaks about the women's labor movement. At that time, conditions in factories, where many women worked, were horrible. A fire at a clothing factory in New York killed 146 people. Most of the victims were immigrant women. A month after Mr. Oppenheim's poem was published, textile workers in Lawrence, Massachusetts, went on strike. Their protest won them higher pay and better working conditions. Oppenheim's poem gained more attention. We close with Pat Humphries singing "Bread and Roses." Even though Labor Day demonstrations are not as common in the U.S., the song reminds us to celebrate the effort and love that many people give to their work. I'm Jim Tedder.