In an inverted pyramid, the most important information is in the first or the first and second paragraphs which bear the 5 WS (who, what, where, when, why(and sometime How) and which constitutes the lead, the gist or the main idea of the entire news story. The rest of the body paragraphs contain less important information. The concept of having the most important information in the first or the second paragraph, known as the lead paragraph, originated in America during the Civil War when newspaper correspondents sent their news by telegraph or wire. Because they were afraid of malfunction of the telegraph system, or the enemy would cut the wires, they fed the most important information in the first few sentences. The inverted pyramid form has been adopted by most newspapermen because it has more advantages both for the reader and editor. For one thing, it gives readers the convenience of grasping the news of the day by simply skimming the lead paragraphs.
Also, it saves their time in continuing reading the story since the lead paragraph contains all the main idea. As for the editors, they may trim the news story from the bottom up if there is not enough space available or they judge that the story is not worth the reader's attention.