The pound or pound-mass is a unit of mass used in both the British imperial and United States customary systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly 0.45359237 kilograms, and which is divided into 16 avoirdupois ounces. The international standard symbol for the avoirdupois pound is lb; an alternative symbol is lbm, #, and ℔ or ″̶.
The ounce is any of several different units of mass, weight, or volume and is derived almost unchanged from the uncia, an Ancient Roman unit of measurement.
The following systems arose from earlier systems, and in many cases utilise parts of much older systems. For the most part they were used to varying degrees in the Middle Ages and surrounding time periods. Some of these systems found their way into later systems, such as the Imperial system and even SI.
A league is a unit of length. It was common in Europe and Latin America, but is no longer an official unit in any nation. Derived from an ancient Celtic unit and adopted by the Romans as the leuga, the league became a common unit of measurement throughout western Europe. Since the Middle Ages, many values have been specified in several countries, ranging from 2.2 km to 7.9 km.
The palm is an obsolete anthropic unit of length, originally based on the width of the human palm and then variously standardized. The same name is also used for a second, rather larger unit based on the length of the human hand.
The units of measurement of ancient Rome were generally consistent and well documented.
The earliest recorded systems of weights and measures originate in the 3rd or 4th millennium BC. Even the very earliest civilizations needed measurement for purposes of agriculture, construction and trade. Early standard units might only have applied to a single community or small region, with every area developing its own standards for lengths, areas, volumes and masses. Often such systems were closely tied to one field of use, so that volume measures used, for example, for dry grains were unrelated to those for liquids, with neither bearing any particular relationship to units of length used for measuring cloth or land. With development of manufacturing technologies, and the growing importance of trade between communities and ultimately across the Earth, standardized weights and measures became critical. Starting in the 18th century, modernized, simplified and uniform systems of weights and measures were developed, with the fundamental units defined by ever more precise methods in the science of metrology. The discovery and application of electricity was one factor motivating the development of standardized internationally applicable units.
In Guatemala the metric system is official but it uses a mixture of U.S., metric and Spanish customary units.
The term "cuerda" refers to a unit of measurement in some Spanish-speaking regions, including Puerto Rico, Guatemala, Cuba, Spain, and Paraguay. In Puerto Rico, the term cuerda refers to the unit of area measurement. In Guatemala, cuerda is both a unit of length measurement as well as of area measurement. As a unit of area measurement, the Guatemalan cuerda can have various meanings. In Cuba, cuerda refers to a unit of volume measurement; in Spain and Paraguay, it refers to a unit of distance (length).
A number of different units of measurement were used in Argentina as its national system was derived from Spanish Castillian. The metric system was legally optional since 1863 and has been compulsory since 1887.
A number of different units of measurement were used in Brazil to measure quantities including length, area, volume, and mass as those units were derived from Portugal and had significant local variances.
A number of different units of measurement were used in Chile to measure quantities like length, mass, area, capacity, etc. From 1848, the metric system has been compulsory in Chile.
A variety of units of measurement were used in Colombia to measure quantities like length, mass and area. In Colombia, International Metric System has adopted since 1853, and has been compulsory since 1854.
A number of units of measurement were used in Honduras for length, mass, volume etc. In Honduras, the metric system was adopted in 1910, and has been compulsory since 1912, under a joint convention between Costa Rica, Guatemala, Honduras, Nicaragua and El Salvador.
A number of units of measurement were used in Nicaragua to measure measurements in mass, area, volume, etc. In Nicaragua, the metric system was adopted in 1910, and has been compulsory since 1912, by a joint convention between Costa Rica, Guatemala, Honduras, Nicaragua and El Salvador.
A number of units of measurement were used in Mexico to measure length, mass, area, capacity, etc. The Metric system was optional from 1857, and has been compulsory since 1896.
A number of units of measurement were used in Paraguay to measure quantities including length, mass, area, capacity, etc. Metric system had been optional since 1890, and adopted since 1899 in Paraguay.
A number of units of measurement were used in Venezuela to measure quantities like length, mass, etc. Metric system was optional in Venezuela since 1857, and has been compulsory since 1914.
Texas, along with the original thirteen states and several others in the Southwest which were originally deeded with Spanish land grants, does not use the Public Land Survey System. Land grants from the state of Texas to railroad companies were often patented in blocks and sections, and occasionally in units of square miles, officially considered sections.
