In what book of the bible do we find the source of human dignity

Explanation:

I have picked out three. I'm not sure that these are the sources, but they do show the qualities of human dignity.

Matthew 7:12 ESV  

“So whatever you wish that others would do to you, do also to them, for this is the Law and the Prophets."

This next one may be closer to what you seek.  It states what God's intention may have been. Put another way, it states what he intended us to be.

Genesis 1:27 ESV

So God created man in his own image, in the image of God he created him; male and female he created

Equality always speaks of human dignity.

Galatians 3:28 ESV

There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus.

There are others. These three speak most to me about human diginity. You can find more by searching for The source of Human Dignity in the Biblel

was a long, primarily nonviolent series of events to bring full civil rights and equality under the law to all americans. the era has had a lasting impact on united states society, in its tactics, the increased social and legal acceptance of civil rights, and in its exposure of the prevalence and cost of racism. in the south violence and fraud in southern elections from 1868 to 1876, which had reduced black voter turnout and enabled southern white democrats to regain power in state legislatures across the south