This is an easy question to answer and you don't need history to prove it. Read whatever bible you want and while your reading it, look for easily verifiable contradictions. You will find them in all versions except the KJV.
For example, the NIV (and others) contradicts itself in regards to the sons of God. In one place it says Israel is God's firstborn son then in another place it says Jesus is God's one and only son. Jesus can't be Gods one and only son if Israel was God's firstborn son, this is an undisputable contradiction and you will not find these contradictions in the KJV.
Exodus 4:22 New International Version (NIV)
22 Then say to Pharaoh, ‘This is what the Lord says: Israel is my firstborn son,
John 3:16 New International Version (NIV)
16 For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.
For example, the NIV (and others) contradicts itself in regards to the sons of God. In one place it says Israel is God's firstborn son then in another place it says Jesus is God's one and only son. Jesus can't be Gods one and only son if Israel was God's firstborn son, this is an undisputable contradiction and you will not find these contradictions in the KJV.
Exodus 4:22 New International Version (NIV)
22 Then say to Pharaoh, ‘This is what the Lord says: Israel is my firstborn son,
John 3:16 New International Version (NIV)
16 For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life.
And thou shalt say unto Pharaoh, Thus saith the LORD, Israel is my son, even my firstborn
(Exodus 4:22, KJV)
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
(John 3:16, KJV)
(Exodus 4:22, KJV)
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
(John 3:16, KJV)
heh.