MINAS GERAES (i.e. “general mines”), popularly Minas, an inland state of Brazil, bounded N. by Goyaz and Bahia, E. by Bahia, Espirito Santo and Rio de Janeiro, S. by Rio de Janeiro and São Paulo, and W. by São Paulo, Matto Grosso and Goyaz. It is very irregular in outline and covers an area of 221,861 sq. m. upon the great Brazilian plateau. Among the Brazilian states it is fifth in size and first in population—3,184,099 in 1890, and 3,594,471 in 1900.
The surface of Minas Geraes is broken by mountain ranges and deeply eroded river courses, the latter forming fertile valleys shut in by partly barren uplands, or campos. The reckless destruction of forests along the watercourses also adds to the barren aspect of the country. The principal mountain ranges are the. Serra da Mantiqueira on its southern frontier and its N. extension, the S. do Espinhaço, which runs parallel to the Serra do Mar, or coast-range, and separates the inland or campo region from a lower forested zone between the two ranges. Most of the wooded district south of the Mantiqueira belongs to the states of São Paulo and Rio de Janeiro, but east of the Espinhaço it belongs to Minas Geraes and extends eastward to the Serra das Aymores, on the frontier of Espirito Santo. This zone has an abundant rainfall, dense forests and a fertile soil. It is drained by the Doce, Mucury, Jequitinhonha and Pardo, which have their sources on the eastern slopes of the Espinhaço and cut their way through the Aymores to the sea. The tributaries of the Rio Doce cover the slopes of the Serra do Espinhaço for a distance north and south of about 200 m. The southern part of this region is well populated, and is covered with coffee and sugar plantations. On the western frontier a northern extension of the great central chain of Goyaz forms the water-parting between the drainage basins of the São Francisco and Tocantins, and is known at different points as the Serra do Paranan, Serra de São Domingos and Serra das Divisöes. South-east of this chain, between the headwaters of the Paraná and São Francisco, are the Serra da Canastra and Serra da Matta da Corde, an irregular chain of moderate elevation running north and south. The highest elevations in the state, so far as known, are Itatiaya (8898 ft.) in the Serra da Mantiqueira, and Caraça (6414 ft.), near Ouro Preto, in the Serra do Espinhaço. The hydrography of the campo region of Minas Geraes is extremely complicated. The Mantiqueira-Espinhago chain shuts out the streams flowing directly east to the Atlantic, and the boundary ranges on the west shut out the streams that flow into the Tocantins, though their sources are on the actual threshold of the state. Between these two mountain chains the head streams of the Paraná and São Francisco are intermingled—the one flowing inland and southward to the great La Plata estuary, the other northward and eastward across the arid highlands of Brazil to the Atlantic coast in 10° 30′ S. lat. Less than 100 m. from the city of Rio de Janeiro and about 60 m. from the coast is the source of the Rio Grande, the larger of the two rivers that form the Parana. It rises near the peak of Itatiaya, on the northern slopes of the Mantiqueira, and flows north-west and west across the Minas plateau, receiving several large tributaries from the south. North and parallel with its course is a low watershed, which separates its drainage basin both from that of the São Francisco and from that of the Parnahyba, the northern confluent of the Parana. The latter rises on the western slopes of the Serra da Matta da Corde, and one of its northern tributaries has its source in a “knot” of the Serra dos Pyreneos, from which streams flow eastward to the São Francisco and northward to the Tocantins. The central and greater part of the state, however, is included in the drainage basin of the upper São Francisco. Its source is in the Serra da Canastra, and its general course across the state is north by east, during which it receives the Paracatu, Urucuia, Pardo and Carinhanha from the west and the Verde Grande and das Velhas from the east. Part of these rivers are navigable for small steamers, and the São Francisco must some day be of great importance in the development of Central Brazil. All these rivers of the Brazilian plateau are interrupted by falls and rapids. The climate of Minas Geraes is characterized by high sun temperatures and cool nights, the latter often dropping below the freezing point on the higher campos. The mean annual temperature is about 85° in the São Francisco valley, 77° on the Campos of the S.E., and 70° on the campos of the W. The year is divided into two seasons—wet and dry—the former lasting from November to May. This division is not so clearly marked in the south, especially in the “matta” (forest) regions, where the rainfall ranges from 59 to 65 in. There is much malaria in the wooded districts of the east and on the higher campos, where the daily extremes of temperature are great, lung and bronchial diseases are common. Some of the high plains, however, as at Barbacena, serve as health resorts for the coast districts.
Minas Geraes is a mining state, though the mining industry has lost much of its importance through the decline in the output of gold and diamonds. Gold is widely diffused, and abandoned “washings” all over the state show how general the industry was at one time. There were in 1908 five deep mines worked by English companies and one by a French company. One of these, the Morro Velho mine, belonging to an English company, is not only the deepest gold-mine in existence (over 2000 ft.), but it has been worked since 1725, and since 1835 by its present owners. Silver is not mined by itself, but is found in combination with gold. In 1908 a rich goldfield was discovered in the northern part of the state, 5 m. from Montes Claros, in the valley of the Verde Grande River, and attracted large numbers of miners. There are many rich deposits of iron ores in the state, but they only produce a small quantity of charcoal iron for local consumption. Manganese ore is mined for export, and bismuth is reported to have been discovered. Minas Geraes is most widely known for its diamonds, which are found in widely separated parts of the state. The largest and most productive field is that of Diamantina (q.v.) on the head-waters of the Jequitinhonha River, where diamonds were discovered about 1725, and where the celebrated “diamond reservation”—an oval-shaped territory 8 leagues wide by 16 leagues long (Mawe), with Tejuco, now Diamantina, very nearly in the centre—was established in 1750. The mines became crown property, gold-mining was forbidden, and no one was permitted to enter the reservation without a licence. The state monopoly was abolished in 1832, and mining has since been carried on by private enterprise. John Mawe estimates that the annual product was 1000 oz. during the first twenty years, and Castelnau estimates the value of the total output down to 1849 at 300,000,000 fr. No estimate can be made of the contraband, which must have been large. A great decline in the output occurred during the last half of the 19th century; but a new field was discovered in 1908 at Abbadia dos Dourados, in the western part of the state. Other valuable stones, the topaz, chrysolite, aquamarine amethyst and tourmaline are found.
Agriculture and grazing have become the main dependence of the population—the former in the lower, forested region of the south-east, where coffee and sugar-cane are the principal products, and the latter on the higher campos and river valleys, and on the mountain slopes, where large herds of cattle are to be found, and milk, butter and cheese are produced. The shipping of fresh milk to Rio de Janeiro and butter-making are comparatively new industries. The river valleys of the campo region are also cultivated to some extent. Among the general products are Indian corn, tobacco, mandioca, beans, pork and cotton. Wheat has been produced in some localities, but not on a paying basis, and experiments have also been made with tea. There is a large variety of fruits, and the cultivation of grapes for wine-making is developing into a profitable industry. Railway communication with Minas Geraes includes the following lines: the Central do Brazil (formerly known as the Dom Pedro II.), which starts from Rio de Janeiro and penetrates nearly to Pirapora (its objective point), at the head of navigation of the São Francisco River, with branches into neighbouring districts; the Leopoldina, from Rio de Janeiro into the forested region of eastern Minas; the Minas and Rio, from Cruzeiro, on the São Paulo branch of the Central do Brazil, into southern Minas; the Mogyana, from Campinas, São Paulo, and runs to Uberaba in western Minas, and is intended to cross into Goyas; and the Bahia & Minas, from the port of Caravellas, in southern Bahia, which runs a short distance into Minas Geraes, and is planned to extend to Philadelphia and beyond. Another line from the port of Victoria, Espirito Santo, northward to Diamantina, Minas Geraes, was under construction in 1908. River transport has some local value on the upper São Francisco and its larger tributaries, and this will be greatly increased when the Central do Brazil railway reaches the head of navigation on that river.
The population of Minas Geraes is chiefly of Portuguese origin, which has been constantly strengthened by immigrants from the mother country. A considerable admixture from other nationalities has resulted from the influx of mining adventurers, and some German colonies have been established in the state. The negro population is large, and there is a still larger contingent of mixed races. The capital is Bello Horizonte (q.v.), or Cidade de Minas; other important cities and towns are: the former capital, Ouro Preto, Barbacena, Diamantina, Baependy (pop. 22,817 in 1890), on the head-waters of the Rio Verde, the centre of a rich tobacco-producing district; Curvello (8071), north of Sabará in the Rio das Velhas Valley, the centre of a cotton growing district and cotton manufactures; Entre Rios (7681), in the coffee district of south-east Minas; Januaria (5888), a river port of the São Francisco in northern Minas; Juiz de Fóra; Marianna (4751), an episcopal town east of Ouro Preto, Mar de Hespanha (18,712), the centre of a productive and populous agricultural municipality of south-east Minas; Paracatú (21,418), an important commercial centre of western Minas near the Goyaz frontier; Queluz (12,600), on the Central do Brazil railway; Congonhas do Campo (10,902), in the municipality of Queluz, celebrated for its miracle-working image, its great church and chapels, and the pilgrimages to its shrine; Sabará (4959), a railway junction on the Central do Brazil, and port on the Rio das Velhas; Congonhas de Sabará (14,066), in the municipality of Sabará, where the celebrated Morro Velho gold-mine is situated; São João d’ El-Rei (15,820) an important commercial mining and pastoral centre, near the Rio das Mortes, connected with the Central do Brazil railway by a branch called the Oeste de Minas; and Uberaba (12,231), a commercial town of the western campos of Minas, connected with São Paulo by the Mogyana and São Paulo railways.
Minas Geraes was first explored by Fernando Dias Paes Leme between 1664 and 1677, though he was not the first European to penetrate it. The discovery of gold in 1692–1695 by bands of adventurers from the São Paulo settlements, led to every occupation and profession being abandoned in the mad rush for the new mines. Minas Geraes at first formed part of the capitania of São Paulo, but in 1720 it became a separate government and was brought more directly under the Portuguese crown. The arbitrary restrictions imposed upon the colonists aroused dissatisfaction among them and eventually led to conspiracy in 1789, inspired by a fear that the Portuguese government was about to enforce the collection of its “fifths” of the mining output, which had largely fallen into arrears. Among the conspirators was one José Alves Maciel, who had just returned from France where he had met Thomas Jefferson and had become infected with French revolutionary ideas. A number of residents became involved, among them the poet Thomaz Antonio Gonzaga. Reckless talk in public places led to the arrest of the conspirators. Only one was executed, a poor, uneducated subaltern militia officer Joaquim José da Silva Xavier, nicknamed O Tiradentes (the Tooth-puller), the others being imprisoned or banished. Tiradentes has since been glorified as the pro-martyr of Brazilian independence. In 1822 Minas became a province of the empire created by Dom Pedro I., though a revolutionary outbreak had occurred in Ouro Preto the year before. In 1842 a long series of quarrels in Rio de Janeiro culminated in a revolution in Minas Geraes and São Paulo, which was suppressed at Santa Luzía, Minas Geraes, on the 20th of August of that year. The abolition of slavery in 1888 caused much discontent among the planters and in the following year Minas Geraes promptly adhered to the declaration of the republic in Rio de Janeiro.