ALL of my young readers must know what a wonderful age this is that we live in, and what marvelous things have been done. Some of you, no doubt, have read the stories of magic in the "Arabian Nights Entertainments," and thought them very odd, if not absurd. But if any one, a hundred years ago, had been told about the railroad, the telegraph, the photograph, the phonograph, vessels that run beneath the surface of the water, and ships that sail in the air, I fancy they would have called all this nonsense and "Arabian Nights" magic. Why, think of it, a trolley car is as magical, in its way, as Aladdin's wonderful lamp. But while you know much about these things, there has been one great step of progress which, I fancy, you know or think very little about. I do not mean material but moral progress, for you must bear in mind that while the world has been growing richer it has also been growing better. A hundred years ago many millions of men were held as slaves in America and Europe. Some of these were black and some were white, but they could be bought and sold like so many cattle, could be whipped by their masters, and had no more rights than so many brute beasts. To-day there is not a slave in Europe or America. All these millions of slaves have been set free. Do you not think I am right in saying that the world has grown better as well as richer? Why, fifty years ago there were millions of slaves in our own country, and now there is not one in all the land. Is not that a great gain to mankind? But it is sad to think that this slavery gave rise to a terrible war. I shall have to tell you about this war, after I have told you how slavery brought it on. In the early part of this book you read of how white men first came to this country. I have now to tell you that black men were brought here almost as soon. In 1619, just twelve years after Captain John Smith and the English colonists landed at Jamestown, a Dutch ship sailed up the James River and sold them some negroes to be held as slaves. You remember about Pocahontas, the Indian girl who saved the life of Captain John Smith. She was afterwards married to John Rolfe, the man who first planted tobacco in Virginia. John Rolfe wrote down what was going on in Virginia, and it was he who told us about these negroes brought in as slaves. This is what he wrote: "About the last of August came in, a Dutch marine-of-war, that sold us 20 Negars." These twenty "Negars," as he called them, grew in numbers until there were four million negro slaves in our country in 1860, when the war began. There are twice that many black people in the country to-day, but I am glad to be able to say that none of them are slaves. Yet how sad it is to think that it cost the lives of hundreds of thousands of men, and misery to multitudes of families, to set them free.