A description of the miserable living standards of the mill workers in England in 1844 was given by Fredrick Engels in The Condition of the Working Class in England in 1844. In the preface to the 1892 edition, Engels noted that the extreme poverty he had written about in 1844 had largely disappeared. David Ames Wells also noted that living conditions in England had improved near the end of the 19th century and that unemployment was low. The scarcity and the high price of labor in the US in the 19th century was well documented by contemporary accounts, as in the following:

"The laboring classes are comparatively few in number, but this is counterbalanced by, and indeed, may be one of the causes of the eagerness by which they call in the use of machinery in almost every department of industry. Wherever it can be applied as a substitute for manual labor, it is universally and willingly resorted to.... It is this condition of the labor market, and this eager resort to machinery wherever it can be applied, to which, under the guidance of superior education and intelligence, the remarkable prosperity of the United States is due." Scarcity of labor was a factor in the economics of slavery in the United States. As new territories were opened and federal land sales were conducted, land had to be cleared and new homesteads established. Hundreds of thousands of immigrants annually came to the US and found jobs digging canals and building railroads.
Thyroid hormone resistance (also resistance to thyroid hormone (RTH), and sometimes Refetoff syndrome) describes a rare syndrome in which the thyroid hormone levels are elevated but the thyroid stimulating hormone (TSH) level is not suppressed, or not completely suppressed as would be expected. The first report of the condition appeared in 1967. Essentially this is decreased end organ responsiveness to thyroid hormones. A new term "impaired sensitivity to thyroid hormone" has been suggested in March 2014 by Refetoff et al. Presentation
The syndrome can present with variable symptoms, even between members of the same family harboring the same mutation. Typically most or all tissues are resistant to thyroid hormone, so despite raised measures of serum thyroid hormone the individual may appear euthyroid (have no symptoms of over- or underactivity of the thyroid gland). The most common symptoms are goiter and tachycardia. It has also been linked to some cases of attention deficit hyperactivity disorder (ADHD), although the majority of people with that diagnosis have no thyroid problems. An association with depression has been proposed. Causes
Normal thyroid hormone function requires normal thyroid hormone transport across cell membrane, appropriate deiodination, thyroid hormone nuclear receptor, thyroid hormone response elements, co-activators, co-repressors, and normal histone acetylation.