The prophet Isaiah describes what had happened to the people of Judah and Jerusalem.
Their land is filled with silver and gold, and there is no end to their treasures; their land is filled with horses, and there is no end to their chariots. (Isaiah 2:7 ESV)
The nation had come to depend on instruments of war rather than the LORD God.
Before the entry into the promised land, the LORD said that His people would desire a king. He laid down restrictions for that king. One of the stipulations is stated this way:
Only he must not acquire many horses for himself or cause the people to return to Egypt in order to acquire many horses, since the LORD has said to you, ‘You shall never return that way again.’ (Deuteronomy 17:16 ESV)
Solomon is especially noted for his trade in horses and chariots from Egypt (1 Kings 10:28-29).
Ahab, king of the northern kingdom of Israel, had a powerful army. The Assyrian king Shalmanesser III met Ahab and 11 other kings in the Battle of Qarqar in 853 B.C. The stone monolith from Kurkh records that Ahab provided 2,000 chariots and 10,000 foot soldiers to the confederacy.
Stables have been uncovered during excavations at Megiddo. The town is so clearly associated with horses and chariots that a metal sculpture has been erected at the site.
Because Megiddo was located on the main trunk road between Egypt and the empires of the north (Hittites and Syria) and those of the east (Assyria, Babylon, and Persia), we should not find this surprising.
Solomon is said to have built the house of the LORD, his own house, the Millo and the Wall of Jerusalem, and the cities of Hazor, Megiddo, and Gezer (1 Kings 9:15). The same context makes reference to chariot cities built by Solomon:
and all the store cities that Solomon had, and the cities for his chariots, and the cities for his horsemen, and whatever Solomon desired to build in Jerusalem, in Lebanon, and in all the land of his dominion. (1 Kings 9:19 ESV
Isaiah was spot-on.