Cover illustration shows mine worker firing a gun after his wife and children were killed in a massacre at their tent camp by the Colorado National Guard and Colorado Fuel & Iron Company camp guards. The Masses Publishing Co., 1914. Library of Congress

A lot more than 2,000 miles separated the Rockefeller estate from Southern Colorado when on Monday April 20, 1914, the first shot was fired at Ludlow. One of history's most dramatic confrontations between capital and labor — the so-called Ludlow Massacre — took place at the mines of the Rockefeller-owned Colorado Fuel and Iron Company (CF&I).

The face-off raged for 14 hours, during which the miners' tent colony was pelted with machine gun fire and ultimately torched by the state militia. A number of people were killed, among them two women and 11 children who suffocated in a pit they had dug under their tent. The deaths were blamed on John D. Rockefeller, Jr. For years, he would struggle to redress the situation — and strengthen the Rockefeller social conscience in the process.

Contemporary voices provide a rare window into the divide that separated the Rockefellers from some of the harsh realities tied to their business decisions. They powerfully illustrate the clashing viewpoints that were at the heart of the crisis and shed light on Rockefeller's ultimate transformation.

September 17, 1913: Official call to go on strike

All mineworkers are hereby notified that a strike of all the coal miners and coke oven workers in Colorado will begin on Tuesday, September 23, 1913 … We are striking for improved conditions, better wages, and union recognition. We are sure to win.

October 1913: John D. Rockefeller Jr. to CF&I vice president Lamont Bowers after beginning of strike

We feel that what you have done is right and fair and that the position you have taken in regard to the unionizing of the mines is in the interest of the employees of the company. Whatever the outcome, we will stand by you to the end.

October 21, 1913: Lamont Bowers to Rockefeller

Our net earnings would have been the largest in the history of the company by $200,000 but for the increase in wages paid the employees during the last few months. With everything running so smoothly and with an excellent outlook for 1914, it is mighty discouraging to have this vicious gang come into our state and not only destroy our profit but eat into that which has heretofore been saved.

October 1913: Federal mediator Ethelbert Stewart comments on the situation

Theoretically, perhaps, the case of having nothing to do in this world but work, ought to have made these men of many tongues, as happy and contented as the managers claim … To have a house assigned you to live in … to have a store furnished you by your employer where you are to buy of him such foodstuffs as he has, at a price he fixes … to have churches, schools … and public halls free for you to use for any purpose except to discuss politics, religion, trade-unionism or industrial conditions; in other words, to have everything handed down to you from the top; to be … prohibited from having any thought, voice or care in anything in life but work, and to be assisted in this by gunmen whose function it was, principally, to see that you did not talk labor conditions with another man who might accidentally know your language — this was the contented, happy, prosperous condition out of which this strike grew … That men have rebelled grows out of the fact that they are men.

December 8, 1913: Rockefeller to Lamont Bowers

You are fighting a good fight, which is not only in the interest of your own company but of other companies of Colorado and of the business interests of the entire country and of the laboring classes quite as much. I feel hopeful the worst is over and that the situation will improve daily. Take care of yourself, and as soon as it is possible, get a little let-up and rest.

April 6, 1914: Rockefeller defends "open shop" before Congressional committee

"These men have not expressed any dissatisfaction with their conditions. The records show that the conditions have been admirable … A strike has been imposed upon the company from the outside …

"There is just one thing that can be done to settle this strike, and that is to unionize the camps, and our interest in labor is so profound and we believe so sincerely that that interest demands that the camps shall be open camps, that we expect to stand by the officers at any cost."

"And you will do that if it costs all your property and kills all your employees?"

"It is a great principle."

April 21, 1914: New York Times' account of the massacre

The Ludlow camp is a mass of charred debris, and buried beneath it is a story of horror imparalleled [sic] in the history of industrial warfare. In the holes which had been dug for their protection against the rifles' fire the women and children died like trapped rats when the flames swept over them. One pit, uncovered [the day after the massacre] disclosed the bodies of 10 children and two women.

April 21, 1914: Rockefeller to Lamont Bowers

Telegram received … We profoundly regret this further outbreak of lawlessness with accompanying loss of life.

April 28, 1914: Socialist writer Upton Sinclair's open letter to Rockefeller

I intend to indict you for murder before the people of this country. The charges will be pressed, and I think the verdict will be "Guilty."

I cannot believe that a man who dares to lead a service in a Christian church can be cognizant and therefore guilty of the crimes that have been committed under your authority.

We ask nothing but a friendly talk with you. We ask that in the name of the tens of thousands of men, women and children who are this minute suffering the most dreadful wrongs, directly because of the authority which you personally have given.

June 10, 1914: Rockefeller's version of the events

There was no Ludlow massacre. The engagement started as a desperate fight for life by two small squads of militia against the entire tent colony … There were no women or children shot by the authorities of the State or representatives of the operators … While this loss of life is profoundly to be regretted, it is unjust in the extreme to lay it at the door of the defenders of law and property, who were in no slightest way responsible for it.

September 1914: Abby Rockefeller to John D. Rockefeller, Jr.

I am writing more and more to urge you to leave to me the petty details of the houses, places, etc. even though I realize they will not be as well or as inexpensively done; and throw the full force of your thought and time into the big, vital questions that come before you.

January 26, 1915: Rockefeller's testimony before the United States Commission on Industrial Relations

"I should hope that I could never reach the point where I would not be constantly progressing to something higher, better -- both with reference to my own acts and … to the general situation in the company. My hope is that I am progressing. It is my desire to."

"You are, like the church says, 'growing in grace?'"

"I hope so. I hope the growth is in that direction."

September 20, 1915: Rockefeller speaks to the miners

We are all partners in a way. Capital can't get along without you men, and you men can't get along without capital. When anybody comes along and tells you that capital and labor can't get along together that man is your worst enemy. We are getting along friendly enough here in this mine right now, and there is no reason why you men cannot get along with the managers of my company when I am back in New York.

September, 1915: United Mine Workers' leader John Lawson comments on Junior's visit to Colorado

I believe Mr. Rockefeller is sincere … I believe he is honestly trying to improve conditions among the men in the mines. His efforts probably will result in some betterments which I hope may prove to be permanent.

However, Mr. Rockefeller has missed the fundamental trouble in the coal camps. Democracy has never existed among the men who toil under the ground — the coal companies have stamped it out. Now, Mr. Rockefeller is not restoring democracy; he is trying to substitute paternalism for it.