POWER AND EXTENT OF THE MALI EMPIRE
At its peak during the 14th century, the Mali empire controlled an area of well over one million Km2 (approx. three times the size of modern Germany):
At its height, under the reigns of Mansa Musa I and Mansa
Sulaymän, the Mali empire covered the entire Sudan-Sahel region of
West Africa. Many peoples and cultures were thus brought together
under a single political head.
Source: D. T. Niane, 'Mali and the second Mandingo expansion' in the UNESCO 'General History of Africa, vol. 4'
"The Medieval Mali Empire at the end of Mansa Musa's reign (1337 CE)". Attribution
Although the region this area covers has been mostly very poor for the last couple of centuries, in the 14th century and earlier the climate was milder and there was plenty of pastureland. Even in the 16th century when the empire had been in decline for at least a century, Mali was described by the scholar Mahmud Ka'ti as having
"some 400 towns and its soil is most fertile. Among the kingdoms of the
rulers of the world, only Syria is more beautiful. Its inhabitants are
rich and live comfortably."
The Moroccan explorer and scholar Ibn Battuta also emphasizes the abundance of food. Niane also adds:
...an estimate that the population of Mali was some 40-50 million. The
river valleys of the Niger and the Senegal were virtually human
anthills. The capital, Niani, had at least 100 000 inhabitants in the
Information provided by Leo Africanus allows us to estimate that Niani's population was still substantial (at least 60,000) at a time (early 16th century) when it had been in decline for sometime. The empire's source of wealth was quite diverse: tributes, trade, mining (especially gold) and agriculture, the last mentioned employing most of the population. Food was abundant and this agricultural wealth made it possible to support a large army:
The standing army, which included both infantry and cavalry units,
numbered more than 100,000 men at the height of the polity.
Source: Alice Willard, 'Gold, Islam and Camels: The Transformative Effects of Trade and Ideology'. In 'Comparative Civilizations Review, Vol. 28 (1993), No. 28'.
Mali was the largest producer of gold in the world at the time and also had large resources of copper. Salt and cotton were traded with the forest regions to the south (modern day Ghana and Ivory Coast) for yet more gold, as well as the very substantial kola nut trade, and palm oil. The gold, along with slaves and ivory, was sent in caravans across the Sahara (both north and east) in exchange for a variety of items including salt, clothing, iron and Arabian horses for the Malian army's cavalry. The caravans which transported these goods were sometimes enormous (even allowing for some exaggeration), numbering
...more than 12,000 camels. This, by no means among the largest of the caravans
(some of which were reported to have more than 100,000 camels...)
When Musa I annexed Timbuktu in 1324, he and his successors turned it into a cultural centre as well as a major commercial hub for the trade routes across the Sahara, literally putting it on the map (see the Catalan Atlas of 1375 below). Musa also brought with him the Andalusian architect Abu Es Haq es Saheli to construct palaces and mosques in Timbuktu and elsewhere. Timbuktu also became a centre of learning, housing the largest library in Africa since the Library of Alexandria.
MUSA I's WEALTH
How wealthy was Mansa Musa I? He probably ranks among the wealthiest men in history, but modern estimates (unsurprisingly) don't really agree (see here and here, for example). Famed for his wealth in Roman times, Marcus Licinius Crassus' fortune (max. $20 billion according to this estimate) may well have been mere pocket money compared to Musa's modern estimate of $400 billion. Musa was wealthy enough to disrupt the Egyptian economy by spending and giving away huge amounts of gold when he stopped in Cairo on his way to Mecca.
Mansa Musa distributed so much gold as gifts, and the Malians spent
such large amounts in the market, that gold declined in value and did
not recover for several years.
Source: David Conrad, Empires of Medieval West Africa
Whether he is richest person ever, as claimed here, is surely impossible to determine with certainty, and what is often omitted from online sources (here and here, for example) is that
By the time Mansa Musa was ready to return to Mali, he had used up all
his gold, so to get home he had to borrow money at an exorbitant rate
Section of the 1375 Catalan Atlas showing Mansa Musa (bottom, with gold crown - click image to enlarge).
DID MUSA's PREDECESSOR REACH THE AMERICAS BEFORE COLUMBUS?
The short answer is that this is unproven.
The interpretion of the evidence for this is controversial at best. The story that Musa's predecessor Abu Bakr II went off in search of 'the edge of the Atlantic Ocean' with a large fleet comes from a single source, the Arab historian Shihab al-Umari. Even if we choose to accept this story, this by itself is obviously not evidence that Abu Bakr II actually reached the Americas.
The arguments presented in Ivan van Sertima's book They came before Columbus are not accepted by mainstream historians, and Mesoamerican academics have been especially critical. This review by Ronald W. Davis in The International Journal of African Historical Studies is pretty scathing:
his work is a strenuous attempt to extend the boundaries of absurdity
in a genre which has never attracted much rigorous scholarship in the
best of times...its content and format raise questions about the
motivations of everyone involved, from the author to his publishers,
in marketing a relatively expensive, useless publication.
The Welsh archaeologist Glyn Daniel was just as critical, describing Sertima's work as "ignorant rubbish" and "badly argued theories based on fantasies" West African historian Djibril Tamsir Niane is less scathing but also does not accept Sertima has proved his case:
Ivan Sertima, an Afro-American researcher, has a theory that blacks
were the first to sail to America. He has analysed minutely Mexican
and Central American civilizations and finds Mandingo elements in
these cultures. The theory is enticing, but unproved.
There are a number of reviews on the internet, including this anonymous one which are very positive, but none seem to be by well-known academics.
Based on having read about 60 pages of 'They came before Columbus', there do seem to be some obviously misleading and / or false statements. For example, the author claims that the Mali empire was bigger than the Roman empire. In another section, he mentions 'Three Mulattoes of Esmeralda', saying they were the descendants of 17 Africans shipwrecked on the South American coast; all this is basically true, but it is also irrelevant as he omits to mention that the 17 Africans were actually 23 Africans (17 slaves plus 6 free men) who were shipwrecked in 1553.
One of the main arguments for an early African presence in the Americas concerns the 'obviously' negroid features of Olmec statues, the main thing cited being the broad noses on the statues. However, broad noses have more to do with climate than race: people from arid / dry regions tend have longer, narrow noses (moistening the dry inhaled air requires a larger mucuous area) whilst those from tropical regions across the world (Africa, South America, Asia) have broader noses. The article Robbing Native American Cultures (pdf) provides a comprehensive critique of Sertima's work.
Concerning the guanín-tipped spears, these were indeed sent back to Spain by Columbus and tested, and the results were as stated. However, the use of the alloy guanín in the Americas dates back to at least the 1st century AD, some 1200 or more years before the supposed arrival of Abu Bakr II and his fleet.
The Cambridge History of Africa, vol. 3