The growth of the national trade unions was a true index of the condition of business.  Four were organized in 1864 as compared to two organized in 1863, none in 1862, and one in 1861.  During 1865, which marked the height of the intense business activity, six more national unions were organized.  In 1866 industry entered upon a period of depression, which reached its lowest depth in 1867 and continued until 1869.  Accordingly, not a single national union was organized in 1866 and only one in 1867.  In 1868 two new national labor unions were organized.  In 1869 two more unions were formed—­a total of seven for the four depressed years, compared with ten in the preceding two prosperous years.  In the summer of 1870 business became good and remained good for approximately three years.  Nine new national unions appeared in these three years.  These same years are marked also by a growth of the unions previously organized.  For instance, the machinists and blacksmiths, with only 1500 members in 1870, had 18,000 in 1873.  Other unions showed similar gains.

An estimate of the total trade union membership at any one time (in view of the total lack of reliable statistics) would be extremely hazardous.  The New York Herald estimated it in August 1869, to be about 170,000.  A labor leader claimed at the same time that the total was as high as 600,000.  Probably 300,000 would be a conservative estimate for the time immediately preceding the panic of 1873.

Although the strength of labor was really the strength of the national trade unions, especially during the depression of the later sixties, far greater attention was attracted outside as well as inside the labor movement by the National Labor Union, a loosely built federation of national trade unions, city trades’ assemblies, local trade unions, and reform organizations of various descriptions, from philosophical anarchists to socialists and woman suffragists.  The National Labor Union did not excel in practical activity, but it formed an accurate mirror of the aspirations and ideals of the American mechanics of the time of the Civil War and after.  During its six years’ existence it ran the gamut of all important issues which agitated the labor movement of the time.

The National Labor Union came together in its first convention in 1866.  The most pressing problem of the day was unemployment due to the return of the demobilized soldiers and the shutting down of war industries.  The convention centered on the demand to reduce the working day to eight hours.  But eight hours had by that time come to signify more than a means to increase employment.  The eight-hour movement drew its inspiration from an economic theory advanced by a self-taught Boston machinist, Ira Steward.  And so naturally did this theory flow from the usual premises in the thinking of the American workman that once formulated by Steward it may be said to have become an official theory of the labor movement.