And it depends on the time in America. White Christian preachers were almost totally silent during the kidnapping and enslavement of Africans here in America,
False. The whole reason slavery was limited to the Southern US was because of the insistence of the Northern states, where preachers from denominations such as the Congregationalists persuaded the majority of the populace to oppose it. Likewise it was due to the effort of abolitionist Christians in Great Britain that the slave trade in the UK was abolished in 1806.
as well as the genocide of Natives.
Also false. Northern churches were not complicit in this, and instead rather sought to minister and convert the indigenous population. This is also true of the Roman Catholic Church. In Alaska, the Russian Orthodox Church, now the Orthodox Church in America, successfully converted the Aleut and Sitka people to Holy Orthodoxy and was instrumental in ensuring they were not the victims of genocide.
During the Civil War not much from white preachers or white Christians about the ungodly practices.
Nonsense, the Civil War and the Emancipation came about as a result of agitation by Northern churches, particularly the Congregationalists, the Northern Methodists and related groups.
In the 40s, 50s, and 60s when blacks were heavily oppressed, white Southern preachers sounded different talking about love and hate, than from black Christian preachers anywhere else in America.
Some white Southern preachers, not all. Martin Luther King had a number of white allies who joined in his campaign.
There was a time in America blacks couldn't just walk into a white church,
This is also false. While it may have been inadvisable for an African American to enter a Southern Baptist church in the 1920s-50s, the extent to which African Americans were welcome varied depending on denomination and locale. Nowadays there are of course a great many blacks in the SBC, and that denomination has renounced its pro-slavery beginnings and even have moved to call themselves Great Commission Baptists in repudiation of the original reason for their founding.
but don't believe there was ever a time when a white person couldn't walk into a black church.
I am not entirely sure this is the case. It is widely known that during the period of segregation, the African Americans, on the basis of fairness, did often react negatively to encroachment in those facilities set aside for their use, and it was reasonable for them to do so, lest they be deprived of even more.
Is there any evidence of a white conservative Christian leader preaching about the evils of slavery in the South during slavery?.
Yes. Look up Charles Finney, Theodore Weld, and in the UK, John Newton, just to name a few, for there were thousands. Indeed the original reason why the Methodist, Presbyterian and Baptist churches split into Northern and Southern halves was due to the Abolitionist stance of the vast majority of Northern Christians.
One huge difference is white Christian leaders belonged to racist churches like the Westboro Baptist Church.
The Westboro Baptist Church is a grotesque thing, although for all its evils, I have never heard it being described as racist, although if it is also racist that would not surprise me. However, the accusation that white Christian leaders as a group belonged to such churches is an inflammatory falsehood.
Whites have done this to black churches and synagogues of worship since the birth of the Nation. There was a white conservative Christian leader in Phoenix telling his church he prays for President Obama's death. Pastor Greg Locke attacked Joe Biden and called the Pope the biggest pedophile on the planet. I just can't imagine a black Christian leader spewing this type of garbage. And there is a difference in white and black conservative Christian leaders and white and black progressive Christian leaders. Lastly, in the 1960s Jerry Falwell, Bob Jones and other white conservative Christian leaders thought standing up for social justice and equity wasn't the job of Christians like Martin Luther King.
There are undeniably racist white preachers, but they are, like their black counterparts such as Louis Farrakhan, thankfully very much in the minority.
They wanted to keep laws of segregation in place. they wanted to galvanize white conservative Christians as a new voting bloc to pass or keep racist laws they liked. They found they could use abortion that way
There’s a straight line from US racial segregation to the anti-abortion movement.
That is utterly false. The Pro Life movement has a very large number of African American supporters, and it is also worth noting that Planned Parenthood was originally founded to promote eugenics along explicitly racist lines, with a view to reducing the Black population, and that Black infants and mothers have been disproportionately the victims of abortion.
Of course the bible does not make distinctions between the races in regard to its teaching, but our country's history plays a role, and being conservative or progressive does also. Different Christians may differ on eschatology and a few other things, but it worries me to see the lack of love.
It worries me too.