How did the labor unions help the workers?

In many ways. Through unity the workers could apply pressure to the bosses (employers) to force them to increase pay rates to a proper and liveable level (a fair days pay for a fair days work) and the employers were also forced to provide resonable and safe working conditions. Without the unions the workers would still be virtual slaves to the unconscionable actions and whims of the powerfully rich employers. During the reign of the last conservative governments in Australia and under Bush in America, legislation was passed to reduce the power of the unions and increase the power of the multi-national companies and other employers and thereby reduce employees entitlements. Given sufficient time, the conservative and liberal forces would return the ordinary workers back to virtual slavery, with no legal entitlements and heaps of unfair pay scales. ie the condition where they were in before the advent of the unions.