Maryland is a state located on the Atlantic Coast in the Mid-Atlantic region of the United States of America. It is comparable in size to the European country of Belgium. According to the most recent information provided by the U.S. Census Bureau, as of August 2007, Maryland is now the wealthiest state in the United States, with a median household income of $65,144, ahead of New Jersey which had previously held that title.

It was the seventh state to ratify the United States Constitution and bears two nicknames, the Old Line State and the Free State. Its history as a border state has led it to exhibit characteristics of both the Northern and Southern regions of the United States. As a general rule, the rural areas of Maryland, such as Western, Southern, and Eastern Maryland, are more Southern in culture, while densely-populated Central Maryland — areas in the Baltimore and the Washington Beltway Regions — exhibit more Northern characteristics.

Maryland is a life sciences hub with over 350 biotechnology firms, making it the third-largest such cluster in the nation. Institutions and agencies located throughout Maryland include University System of Maryland, Johns Hopkins University, Howard Hughes Medical Institute, the Food and Drug Administration (FDA), and the National Institutes of Health (NIH).

In 1629, George Calvert, 1st Lord Baltimore in the Irish House of Lords, fresh from his failure further north with Newfoundland's Avalon colony, applied to Charles I for a new royal charter for what was to become the Province of Maryland. Calvert's interest in creating a colony derived from his Catholicism and his desire for the creation of a haven for Catholics in the new world. In addition, he was familiar with the fortunes that had been made in tobacco in Virginia, and hoped to recoup some of the financial losses he had sustained in his earlier colonial venture in Newfoundland. George Calvert died in April 1632, but a charter for "Maryland Colony" (in Latin, "Terra Maria") was granted to his son, Cæcilius Calvert, 2nd Lord Baltimore, on June 20, 1632. The new colony was named in honor of Henrietta Maria, Queen Consort of Charles I.

To try to gain settlers, Maryland used what is known as the headright system. On March 25, 1634, Lord Baltimore sent the first settlers into this area. Although most of the settlers were Protestants, Maryland soon became one of the few regions in the British Empire where Catholics held the highest positions of political authority. Maryland was also one of the key destinations of tens of thousands of British convicts. The Maryland Toleration Act of 1649 was one of the first laws that explicitly dictated religious tolerance, although toleration was limited to Trinitarian Christians.

The royal charter granted Maryland the Potomac River and territory northward to the fortieth parallel. This proved a problem, because the northern boundary would put Philadelphia, the major city in Pennsylvania, partially within Maryland, resulting in conflict between the Calvert family, which controlled Maryland, and the Penn family, which controlled Pennsylvania. This lead to the Cresap's War (also known as the Conojocular War), a border conflict between Pennsylvania and Maryland, fought in the 1730s. Hostilities erupted in 1730 with a series of violent incidents prompted by disputes over property rights and law enforcement, and escalated through the first half of the decade, culminating in the deployment of military forces by Maryland in 1736 and by Pennsylvania in 1737. The armed phase of the conflict ended in May 1738 with the intervention of King George II, who compelled the negotiation of a cease-fire. A final settlement was not achieved until 1767, when the Mason-Dixon Line was recognized as the permanent boundary between the two colonies.

After Virginia made the practice of Anglicanism mandatory, a large number of Puritans migrated from Virginia to Maryland, and were given land for a settlement called Providence (now Annapolis). In 1650, the Puritans revolted against the proprietary government and set up a new government that outlawed both Catholicism and Anglicanism. This lasted until 1658, when the Calvert family regained control and re-enacted the Toleration Act. However, after England's "Glorious Revolution" of 1688, when William of Orange and his wife Mary came to the throne and firmly established the Protestant faith in England, Catholicism was again outlawed in Maryland, until after the U.S. Revolutionary War. Many wealthy plantation owners built chapels on their land so they could practice their Catholicism in relative secrecy. During the persecution of Maryland Catholics by the Puritan revolutionary government, all of the original Catholic churches of southern Maryland were burned down.

St. Mary's City was the largest site of the original Maryland colony, and was the seat of the colonial government until 1708. St. Mary's is now an archaeological site, with a small tourist center. In 1708, the seat of government was moved to Providence, which had been renamed Annapolis in honor of Queen Anne in 1694.

Maryland was one of the thirteen colonies that revolted against British rule in the American Revolution. On February 2, 1781, Maryland became the 13th state to approve the ratification of the Articles of Confederation which brought into being the United States as a united, sovereign and national state. It also became the seventh state admitted to the US after ratifying the new Constitution. The following year, in December of 1790, Maryland ceded land selected by President George Washington to the federal government for the creation of Washington, D.C. The land was provided from Montgomery and Prince George's Counties, as well as from Fairfax County and Alexandria in Virginia (though the lands from Virginia were later returned through retrocession). The land provided to Washington, D.C. is actually "sitting" inside the state of Maryland.

During the War of 1812, the British military attempted to capture the port of Baltimore, which was protected by Fort McHenry. It was during this bombardment that the Star Spangled Banner was written by Francis Scott Key.

Despite widespread support for the Confederate States of America among many wealthy landowners, who had a vested interest in slavery, Maryland did not secede from the Union during the American Civil War. This may be due in part to the temporary suspension of the Legislature by Governor Hicks and arrest of many of its fire eaters by Lincoln prior to its reconvening. Many historians contend that the votes for secession would not have been there regardless of these actions. Of the 115,000 men who joined the militaries during the Civil War, 85,000, or 77%, joined the Union army. To help ensure Maryland's inclusion in the Union, President Lincoln suspended several civil liberties, including the writ of habeas corpus, an act deemed illegal by Maryland native Chief Justice Roger Taney, ordered US troops to place artillery on Federal Hill to directly threaten the city of Baltimore and helped ensure the election of a new pro-union governor and legislature. As mentioned above, President Lincoln even went so far as to jail certain pro-South members of the state legislature at Fort McHenry including the grandson of Francis Scott Key. The Constitutionality of these actions is still a source of controversy and debate. Because Maryland remained in the Union, it was exempted from the anti-slavery provisions of the Emancipation Proclamation (The Emancipation Proclamation only applied to states in rebellion). A constitutional convention was held during 1864 that culminated in the passage of a new state constitution on November 1 of that year. Article 24 of that document outlawed the practice of slavery. The right to vote was extended to non-white males in 1867.

Since Maryland had remained in the Union during the Civil War, the state did not undergo reconstruction like the states of the former Confederacy. However, as a former "slave state," Maryland did experience many of the same problems with civil rights and racial tensions as did the rest of the country. The deep divisions in the state between those who fought for the North and those who fought for the South were also difficult to repair.

The Democratic Party regained power in the state from the Republicans who had gained control of the government during the war. With the shift in power away from the Republicans, support for the Constitution of 1864 ended and it was replaced by the Maryland Constitution of 1867. That document, which is still in effect today, resembled the 1851 constitution more than its immediate predecessor and was approved by 54.1% of the state's population. However, while reapportioning the legislature based on population, not counties, which gave greater power to freed slaves, the document undid many of the benefits that the prior constitution had given to the state's African American population.

Over the next several decades, the position of the state's African American population would remain an issue. This matter was brought to the forefront of Maryland politics in 1910 by the proposed Digges Amendment to the state constitution. The amendment would have used property requirements to effectively disenfranchise many African Americans (and possibly some immigrants) in the state. It was passed by the Maryland General Assembly and had the approval of the Governor, Austin Lane Crothers, but it still required the approval of the people. Even before the people even had a chance to vote on the amendment, a bill was proposed which would have effectively passed the requirements of the Digges Amendment into law anyway. Not only did that measure fail (after a public outcry) but the amendment itself was rejected by the voters of Maryland. This was only the most notable rejection of a black-disenfranchising amendment. At least two other defeated proposals, the Poe Amendment in 1905 and the Straus Amendment in 1909, tried to restrict the voting rights of blacks in the state and other such proposals would arise in Maryland over the next several years.

In the early 20th century, a political reform movement arose, centered in the rising new middle class. One of their main goals included having government jobs granted on the basis of merit rather than patronage. Other changes aimed to reduce the power of political bosses and machines, which they succeeded in doing.

In a series of laws passed between 1892 and 1908, reformers distributed ballots which had been pre-marked by the parties replaced with uniform state-issued ballots; obtained closed voting booths to prevent party workers from "assisting" voters; initiated primary elections to keep party bosses from selecting candidates; and had candidates listed without party symbols, which discouraged the illiterate from participating. Although promoted as democratic reforms, the changes had the effect the middle class was seeking. The lower classes and the illiterate were discouraged from going to the polls. Voting participation dropped from about 82% of eligible voters in the 1890s to about 49% in the 1920s.

One more progressive debate had a lasting effect on the state when the debate over prohibition of alcohol led to Maryland gaining its second nickname when a mocking newspaper editorial dubbed Maryland the Free State.

The United States initially tried to avoid involvement in World War I, which many saw as a European conflict. However, the country was eventually pulled into the massive war. This, of course, brought many changes to the nation and Maryland was no exception.

Maryland was the site of many new military bases, like Camp Meade (now Fort Meade) and the Aberdeen Proving Ground, which were established in 1917 and the Edgewood Arsenal, which was founded the following year. Other existing facilities, including Fort McHenry, were greatly expanded.

To coordinate wartime activities in the state, like the expansion of federal facilities, the General Assembly set up a Council of Defense. The 126 seats on the council were filled by many of the state's most prominent citizens. The Council, which had a virtually unlimited budget, was charged with defending the state, supervising the draft, maintaining wage and price controls, providing housing for war-related industries, and promoting support for the war. Citizens were encouraged to grow their own victory gardens and to obey ration laws. They were also forced to work, once the legislature adopted a compulsory labor law with the support of the Council of Defense.

Maryland's experience during the worldwide economic downturn was not particularly unique, though in 1932 the "Bonus Army" marched through the state on its way to Washington, D.C. In addition to the nationwide New Deal reforms of President Roosevelt, Maryland also took steps to weather the hard times. For instance, in 1937 the state instituted its first ever income tax.

Maryland also saw advancements in civil rights. The 1935 case Murray v. Pearson et al resulted in a Baltimore City Court ordering integration of University of Maryland Law School. The plaintiff in that case was represented by Thurgood Marshall, a young lawyer working with the NAACP and a native of Baltimore. The attorney general appealed to the state's highest tribunal, the Court of Appeals, which affired the decision. Because the state did not appeal the ruling in the federal courts, this state ruling under the U.S. Constitution was the first to overturn Plessy v. Ferguson, the 1896 Supreme Court decision approving racial segregation. While it was a moral precedent, it was not a legal one, and had no authority outside the state of Maryland.