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 |
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.
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.
Colonial-style houses are simple rectangular homes that became popular in the 1600s as colonists settled the East Coast. These homes have many variations due to the fact that new communities all over the world built Colonial-style homes to suit their culture.
British Colonial style is the most common and recognizable Colonial home. Its key features include:
- A side-gabled roof
- Two floors
- A centered front door
- Symmetrical windows on either side of the door
The rectangular shape and interest in symmetry are seen in other Colonial house styles, too. Materials and decorative features can vary by region, as some Colonial houses sport brick exteriors and ornate trim, while others showcase shingle siding and simple shutters.
These are also some of the cheapest types of houses to build.
Georgian-style homes were one of the most common styles in the 18th century and showcased formal and classical details that previous homes didn’t. Georgian houses are similar to Federal houses, though they can be distinguished by:
- A crown and pilasters framing the front door
- Decorative quoins or bricks at the corners
- Smooth decorative blocks as moulding
You can also find regional variations with hooded front doors and pent roofs between levels.
Federal-style homes became popular after the American Revolution and were a refined upgrade to the popular Georgian house style. They have the same recurring shape and symmetry as other Colonial house styles, but their delicate ornamentation sets them apart.
Federal Colonial homes often feature:
- A layout built around a central hall
- An elliptical fanlight and two flanking lights (windows) around the door
- Paladin or tripartite windows
The elliptical fanlights and paladin windows are key distinguishing features from Georgian-style homes.
There was a renewed interest in handcrafted art and design following the industrial revolution. This became the “Arts and Crafts” era and paved the way for the Craftsman home, or “arts and crafts” home.
Craftsman homes focus on simplicity to counter the ornate stylings of Victorian homes. They’re also designed to highlight the craftsmanship of its builders and include:
- A low-pitched roof with overhanging eaves
- A covered porch
- Woodwork including exposed beams and built-in features like shelving
- Natural tones to complement the warmth from woodworking
Craftsman homes are favored for their character and are another versatile style that may borrow common elements from other home styles.
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.”
Modern home design became popular in the early 20th century and has a heavy influence on today’s contemporary designs. The core of modern designs can be seen in their:
- Use of geometric shapes
- Large, floor-to-ceiling windows
- Clean lines and flat roofs
- Open floor plans
These styles attempt to connect with nature through minimalism and fluid design between outdoor and indoor spaces. Modern house styles branch into a few key sub-styles.
The American Farmhouse is a simple and timeless style. Farmhouses are designed to be practical first and foremost. They’re common across the US and often showcase regional variations, like wrap-around porches in the South.
Farmhouses have evolved with time and location, but often feature these elements:
- Rectangular floor plan
- Large front porches
- Natural wood and stone materials
- Few and small windows
- Formal front rooms separated from family rooms
Of course, the easiest way to identify a farmhouse is that they’ll often be situated on a large plot of farmland.
Cape Cod homes are similar to the British or American Colonial homes, though they originated further north in Cape Cod, Massachusetts. These are often seen as the classic American family home since the style’s revival in the 20th Century.
Cape Cod homes are identified by their:
- Shingle exteriors
- Modest size and ornamentation compared to British Colonial homes
- Originally single-story homes
- Large central fireplaces
- Attic lofts (20th-century revival)
- Dormer windows (20th-century revival)
Cape Cod homes are built of local wood and stone to withstand the north-eastern weather. This exterior weathering provides an iconic weathered-blue color to these homes.
Prairie-style homes were made famous by the architect Frank Lloyd Wright. These homes celebrate and complement the natural beauty of the Midwestern landscape with low and long shapes in the floor plan and building elements.
Prairie-style houses showcase:
- Long and low-to-the-ground builds
- Flat or shallow roofs with overhanging eaves
- Thin bricks or stucco exteriors to match the house shape
- Minimalist yet stylized ornamentation
Prairie houses inspired the flat planes and natural elements popular in Mid-century houses.
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.