The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the National Academy of Medicine (NAM).
As a national academy, new members of the organization are elected annually by current members, based on their distinguished and continuing achievements in original research. Election to the National Academy is one of the highest honors in the scientific field. Members of the National Academy of Sciences serve pro bono as "advisers to the nation" on science, engineering, and medicine. The group holds a congressional charter under Title 36 of the United States Code.
Founded in 1863 as a result of an Act of Congress that was approved by Abraham Lincoln, the NAS is charged with "providing independent, objective advice to the nation on matters related to science and technology. … to provide scientific advice to the government 'whenever called upon' by any government department."[2]
The Academy receives no compensation from the government for its services.[3]
The Academy currently has 2,984 members and international members. Existing members elect new members for life. Up to 120 members are elected every year; up to 30 foreign citizens may be elected as international members annually. The election process begins with a formal nomination, followed by a vetting period, and culminates in a final ballot at the Academy's annual meeting in April each year. Members are affiliated with a section -- a specific scientific field -- in one of six so-called "classes": (1) Physical and Mathematical Sciences; (2) Biological Sciences; (3) Engineering and Applied Sciences; (4) Biomedical Sciences; (5) Behavioral and Social Sciences; and (6) Applied Biological, Agricultural, and Environmental Sciences.[6] Since its founding, the Academy has elected 6,457 members. Harvard University is associated with the most members (329), some 5% of the all-time total. The top ten institutions, half of which are Ivy League universities, account for nearly 28% of all members ever elected.[11]
| Top 10 Primary Institutions | Members (1963-2022) |
|---|---|
| Harvard University | 329 |
| Stanford University | 250 |
| University of California, Berkeley | 242 |
| Massachusetts Institute of Technology | 206 |
| Yale University | 132 |
| Princeton University | 128 |
| California Institute of Technology | 126 |
| Columbia University | 125 |
| University of Chicago | 120 |
| University of Pennsylvania | 83 |
Ranch house styles are the most searched style in the US today and are common in cities and suburbs across the country. There are various ranch house styles, including California and split-level ranch homes. The main distinguishing features between these styles are living space and home layout.
Ranch style homes feature:
- Single-story floor plans with low-pitched roofs
- Rectangular, “U,” or “L” shaped open floor plans
- Patio or deck space connected to the home
- Often includes a finished basement or attached garage
Ranch homes are the most popular homes in 34 US states — particularly in the Midwest and on the East Coast.
Most Dutch Colonial homes you find today are actually from the Colonial Revival period of the early 20th Century. Original Dutch Colonial homes feature flared roof eaves and creative wood and brickwork. They are much more ornamental than classic Colonial homes, though the Dutch Colonial Revival style tends to be more subdued than the original Dutch Colonial homes.
Dutch Colonial Revival houses feature:
- Broad gambrel roofs that are visually similar to barn-style roofs
- Open-floor plans
- Flared roof eaves
- Split doors
The large barn-style roofs are the most identifiable feature of a Dutch Colonial home and even became known as “Dutch roofs.”
Victorian homes were built between 1837 and 1901 while Queen Victoria reigned in Britain. “Victorian” actually refers to multiple styles that vary in influence, but each features ornate detailing and asymmetrical floor plans.
The key features of a Victorian-era home include:
- Elaborate woodwork and trim
- Towers, turrets, and dormer windows
- Steep gabled roofs
- Partial or full-width porches
Victorian homes are all about ornamentation — industrialization allowed these homes to be produced en masse and across a variety of architectural styles.
Shingle-style homes took influence from Colonial architecture rather than Medieval Europe. Ornamentation became simpler towards the end of the Victorian-era and Shingle-style homes are best known for their creative floor plans and signature shingles on exterior walls.
Shingle Victorian homes are identified by these interior and exterior features:
- Shingles cover the entire exterior
- Asymmetrical interior layouts without a central hallway
- Emphasis on horizontal planes
- Custom built to meld with the nature surrounding the house
Shingle-style houses were designed as a work of art and encouraged creativity in their use of shapes and features.
House styles will continue to evolve with influences from history, culture, and our lifestyles. All of these house styles can be seen and celebrated across the US and have their own stories to tell. Choose the house style that fits your lifestyle, location, and, of course, personal style best. Then check your credit score, get pre-approved, and start house-hunting.
Around the 1820s, Americans experienced a renewed interest in classic Greek and Roman culture. This cultural shift was a natural fit for architects, who brought the Greek Revival house style to life.
Greek Revival architecture became popular in homes as well as businesses, banks, and churches. Prominent features include:
- Easy to identify shapes, including a rectangular building and triangular roofs
- Gable-front designs
- Large porches and protected entryways
- Greek-inspired columns both square and round
Greek Revival homes often have decorative trim and moulding around the front door and windows. These ornate features and columns are easy ways to identify Greek Revival architecture.
Gothic Revival architecture grew in the mid-19th century and was one of the early styles of Victorian-era homes. The Gothic Revival style takes influence from Medieval Europe and was designed as a country home. Architects believed the asymmetrical design and ornamentation complemented the nature of rural America.
Gothic Revival homes can be identified by their:
- Pointed arch in windows, doors, and decoration
- Elaborate wood trim vergeboards and bargeboards
- Steeply pitched roofs and front-facing gables
- Towers and turrets resembling medieval castles
Gothic Revival architecture was a popular style for schools and churches as well as rural homes.
The Parthenon in Centennial Park, in Nashville, Tennessee, is a full-scale replica of the original Parthenon in Athens. It was designed by architect William Crawford Smith and built in 1897 as part of the Tennessee Centennial Exposition.
Today the Parthenon, which functions as an art museum, stands as the centerpiece of Centennial Park, a large public park just west of downtown Nashville. Alan LeQuire's 1990 re-creation of the Athena Parthenos statue in the naos (the east room of the main hall) is the focus of the Parthenon just as it was in ancient Greece. Since the building is complete and its decorations were polychromed (painted in colors) as close to the presumed original as possible, this replica of the original Parthenon in Athens serves as a monument to what is considered the pinnacle of classical architecture. The plaster replicas of the Parthenon Marbles found in the Treasury Room (the west room of the main hall) are direct casts of the original sculptures which adorned the pediments of the Athenian Parthenon, dating back to 438 BC. The surviving originals are housed in the British Museum in London and at the Acropolis Museum in Athens.
The U.S. health system is a mix of public and private, for-profit and nonprofit insurers and health care providers. The federal government provides funding for the national Medicare program for adults age 65 and older and some people with disabilities as well as for various programs for veterans and low-income people, including Medicaid and the Children’s Health Insurance Program. States manage and pay for aspects of local coverage and the safety net. Private insurance, the dominant form of coverage, is provided primarily by employers. The uninsured rate, 8.5 percent of the population, is down from 16 percent in 2010, the year that the landmark Affordable Care Act became law. Public and private insurers set their own benefit packages and cost-sharing structures, within federal and state regulations.
The United States has 63 national parks, which are Congressionally-designated protected areas operated by the National Park Service, an agency of the Department of the Interior.[1] National parks are designated for their natural beauty, unique geological features, diverse ecosystems, and recreational opportunities. While legislatively all units of the National Park System are considered equal with the same mission, national parks are generally larger and more of a destination, and hunting and extractive activities are prohibited.[2] National monuments, on the other hand, are also frequently protected for their historical or archaeological significance. Eight national parks (including six in Alaska) are paired with a national preserve, areas with different levels of protection that are administered together but considered separate units and whose areas are not included in the figures below. The 423 units of the National Park System can be broadly referred to as national parks, but most have other formal designations.[3]
A bill creating the first national park, Yellowstone, was signed into law by President Ulysses S. Grant in 1872, followed by Mackinac National Park in 1875 (decommissioned in 1895), and then Rock Creek Park (later merged into National Capital Parks), Sequoia and Yosemite in 1890. The Organic Act of 1916 created the National Park Service "to conserve the scenery and the natural and historic objects and wildlife therein, and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations."[4] Many current national parks had been previously protected as national monuments by the president under the Antiquities Act or as other designations created by Congress before being redesignated by Congress; the newest national park is New River Gorge, previously a National River, and the most recent entirely new park is National Park of American Samoa. A few former national parks are no longer designated as such, or have been disbanded. Fourteen national parks are designated UNESCO World Heritage Sites (WHS),[5] and 21 national parks are named UNESCO Biosphere Reserves (BR),[6] with eight national parks in both programs.
Thirty states have national parks, as do the territories of American Samoa and the U.S. Virgin Islands. The state with the most national parks is California with nine, followed by Alaska with eight, Utah with five, and Colorado with four. The largest national park is Wrangell–St. Elias in Alaska: at over 8 million acres (32,375 km2), it is larger than each of the nine smallest states. The next three largest parks are also in Alaska. The smallest park is Gateway Arch National Park, Missouri, at 192.83 acres (0.7804 km2). The total area protected by national parks is approximately 52.2 million acres (211,000 km2), for an average of 829 thousand acres (3,350 km2) but a median of only 208 thousand acres (840 km2).[7]
The national parks set a visitation record in 2017, with more than 84 million visitors and set a further record in 2018 with a 0.1% increase.[8][9] Great Smoky Mountains National Park in North Carolina and Tennessee has been the most-visited park since 1944,[10] and had over 14 million visitors in 2021.[11] In contrast, only about 7,000 people visited the remote Gates of the Arctic National Park and Preserve in Alaska in 2021.
Townhomes are common in cities and densely populated neighborhoods. Townhouses are tall and narrow homes designed to make the most out of vertical space without too much of a yard or garden area.
Homes are considered townhouses when they:
- Share one or two walls with adjacent homes
- Have their own entrances
- Are built with multiple floors to maximize vertical space
- Often share a similar style to their neighbors’ homes and may operate under an HOA
Townhouses can be built to mimic other architecture styles, like Italianate and Greek Revival, while maintaining the condensed, vertical floor plan.
