En Mi opinion

Personally I believe that history had an obejective existance that we must recognize as sun-tzu wrote in his book the Art of War that "The state cannot be brought back into existance, the dead cannot be brought back into life" (At that point he was advising generals as to why hasty ill planed revenge attacks was a trait of a bad general) but it is impossible impossible to say for certain if reality is subjective or objective and that is a debate for another time. However it is important that we teach a history that is as inclusive as possible, if nothing else solely for pragmatic reasons. While it is impossible to teach everything, as not everything is known, the primary focus of society should be to show how the past affects the present, and show examples of those who succeed as role models, this includes a vide variety of people from Theodore Roosevelt, Franklin Delanor Roosevelt, John Fitsgerald Kennedy, Martin Luther King, Thurgood Marshall, Ceasar Chavez, Etc. All of these examples are from the 20th century, a more comprehensive list would take pages to transcribe. However if any one group is removed from history it is detrimental to the students that identify themselves as members of that group. For example the study done that was instrumental in the ruling of Brown v. Board of Education showed that society and the segregated school system was detremental to African American students.
Sorry for the obvious retcon, but I wasn't quite finished, but I appreciate the praise none the less. Back to the topic, As stated above there is a pragmatic reason for creating an inclusive history that shows its impact on the present, just as in 1984 the "captialists" were shown in their lowest point the early 1800's in Britain in the U.S. it was the guilded age which took place later, in order to justify the extreme measures that the proles and party members live in. Think of how certain pundits argue over the traits of the founding fathers, ulitmately who cares how often, say Thomas Jefferson went to church? only someone who would like to use that as to justify the continuation of the "Defense of Marrage" Act. And for the proverbial record I doubt someone who would after his wife's death move onto her younger half sister who happened to be a family slave was a bible thumping fundamentalist.