What institutions and organizations existed in the United States before the structured and recognizable labor unions formed as a visible sign of organizations to come? How did these predecessor organizations pave the way for powerful labor organizations as recognized in the twentieth century?
The earliest form of unions were guilds which identified people who specialized in certain skills. These guilds would consist of masters, journeymen, and apprentices, each with different levels of experience. As cities became more urbanized, many industries found it more practical to hire unskilled labor and train them to have the necessary skills.
The earliest form of organized unions were called craft unions, and they consisted of workers within a specific industry who possessed critical skills. They found that by removing these critical workers they could make demands on their employers that would often be met in order to resume production. These generally did little to help unskilled workers, but they did establish a model upon which future unions would be built.
In the late 19th century, trade unions started popping up. These were very similar to craft unions in that they focused on workers with skills in a particular trade. Another form of union that began to appear was industrial unions, which organized workers without regard to trade.
Perhaps the earliest organized union to represent a mass of unskilled workers in the US was a group called the Knights of Labor (KOL). They were formed in Philadelphia in 1869 and grew to a million members by the end of the century. The KOL united workers without consideration of occupation, industry, race or gender.
All information taken from Labor Unions in the United States by Gerald Friedman, University of Massachusetts at Amherst.
Its common to see union histories begun in the late 19th century, but the institutional precursors for labor unions--even unions that organize workers regardless of trade or craft--goes back to the founding of the country. The earliest I know of is the General Society of Mechanics and Tradesman, founded as a mutual aid society for skilled workers in New York City in 1785.
The first wave of formal organization of wage earners started in the 1820s. In Philadelphia, different trades were organized by the Mechanics' Union of Trade Associations, founded in 1827. A similar organization called the General Trades Union was founded in New York City.
Just as important were the political vehicles of the working class, the Working Men's Parties. First founded in 1828, state-by-state experiences varied quite a bit. However, they generally ended up being absorbed by the Democratic Party.
The Panic of 1837 hit these labor organizations hard. Many native workers gave up their political goals and focused on immediate problems like subsistence. During this period, labor activism was kept alive by Irish and German immigrants, who imported their homelands' radical labor culture (Wilentz 1984, pp. 252-253).
In response to these immigrants, a whole new wave of labor organizations were founded in the 1840s and 1850s. These organizations often exhibited a pronounced nativism. They include the Mechanics Mutual Protection Association (Buffalo, 1841), the Order of United American Mechanics (Philadelphia, 1845), and the American Laboring Confederacy. There were also umbrella organizations such as New York's Industrial Congress, which during the 1850s and 1860s received delegates from labor organizations all across the city and met in City Hall.
Source: Sean Wilentz's Chants Democratic is the best single-volume study I know for antebellum labor history.