A person hanging from a rope over a city. New york ny manhattan building.

In 1857 Elisha Otis introduced the safety elevator, allowing easy passenger access to upper floors. A crucial development was also the use of a steel frame instead of stone or brick. An early development in this area was five floors high Oriel Chambers in Liverpool, England. While its height is not considered very impressive today, the world's first skyscraper was the ten-story Home Insurance Building in Chicago, built in 1884–1885. Most early skyscrapers emerged in the land-strapped areas of Chicago and New York City toward the end of the 19th century. In a building like these, a steel frame supported the entire weight of the walls, instead of walls carrying the weight called "Chicago skeleton" construction. 1889 marks the first all-steel framed skyscraper in Chicago, while Louis Sullivan's Wainwright Building in St. Louis, Missouri, 1891, was the first steel-framed building with vertical bands to emphasize the height of the building and is therefore considered by some to be the first true skyscraper. After an early competition between Chicago and New York City for the world's tallest building, New York took the lead by 1895 with the completion of the American Surety Building, leaving New York with the title of the world's tallest building for many years. New York City developers competed among themselves, with successively taller buildings claiming the title of "world's tallest" in the 1920s and early 1930s, culminating with the completion of the Chrysler Building in 1930 and the Empire State Building in 1931, the world's tallest building for forty years.

People keep searching online for one question: "Where can I find free high-resolution stock images that are cleared to use without any copyright restrictions? Where to find images for blog posts or social media?" Almost every image created in the last 70 years is still protected by copyright, but you can find a public domain photo, an image that does not need attribution, or image that has copyright expired. First, it helps to understand some copyright-related terms before using any free images. Always read the terms and conditions of the site you try to use to download free images and photos, so you know if, when, and what type of attribution is required. What is Creative Commons? Creative Commons is a nonprofit organization that enables the sharing and use of creativity and knowledge through free legal tools. There are various types of Creative Commons licenses that range from allowing any type of use with no attribution to allowing only certain uses and no changes. Most authors using Creative Commons require some sort of attribution. While relatively easy to use such free images in blogs, using such images for video might be problematic unless you create lengthy credits section. Even if you do, you still may breach the particular image Creative Commons license since it often requires backlinking. What is Public Domain? Works in the public domain are those whose copyrights have expired or never existed. The public domain status of official government works is sometimes difficult to determine but there are some easy cases: works of the United States federal government, for example, are not protected by copyright and are thus in the public domain. The same does not hold in general for the works of other governments or all 50 States of the United States. Determining whether a particular work of a particular government are in the public domain requires research and sometimes even legal advice. What is Royalty-Free? Most royalty-free images aren’t free. In most cases, you’ll have to pay a one-time fee to obtain the rights to use the image. Then you can use it as many times as you like. The term “free” in “royalty-free” means that you do not have to pay royalties to the owner of the image every time you use it. We've reviewed terms of few popular Free Image Websites below. 1. Unsplash Unsplash has its own license, which essentially lets you use the images for free, in any way you like, except for using them to create a competing website. 2. Pexels Pexels also has its own license, which states what you can and cannot do with the images. You can use and modify the images for free for both commercial and personal use without attribution. 3. Pixabay We love Pixabay. Images on Pixabay are licensed under Creative Commons Zero (CC0), which means you can use the images without asking for permission or giving credit to the artist. Pixabay also explains tricky legal language such as "model release". 4. Gratisography Gratisography also has its own free photo license, which lets you do “almost anything you can think of”. While they have not too many images, many are high-quality images that I would use. 5. Flickr Flickr is where you can find images that can be used and modified for commercial purposes. Select “Commercial use & mods allowed” under the “Any license” filter to find those images, and remember to check the license for each image as they vary. Be careful with Flickr images since as far as we can see, many images are labeled public domain wrongfully or without much research. 6. Google Image Search Google Advanced Image Search is a method of finding free-to-use images through Google’s own search tools. It is 100% automated, so you can't blindly trust the license cited. Use it with caution. Same as Flickr, Google bears no responsibility. When using free online images, always do your research.