The history of Scots-Irish Immigration to America should perhaps start with the origin of the name. Scots-Irish or Scotch-Irish? Both are correct in America. In the UK the use of word Scotch for Scots or Scottish is felt to be incorrect, especially when applied to people.  

History of Scots-Irish Immigration to America: Religion
Scots-Irish people trace their ancestry to Scotland and descend from Presbyterians who originated in the Scottish lowlands, but emigrated to Ireland. The term Scots-Irish originated in America to distinguish the Protestant Irish of Scottish ancestry with the Irish Catholics. It should be remembered that Colonial America was largely a Protestant country and it was important for these early settlers to differentiate themselves from Irish Catholics. Also refer to Examples of PUSH and PULL Factors of Scots-Irish Immigration.

History of Scots-Irish Immigration to America: The Highlanders and the Lowlanders
Scotland is separated into the northern Highlands and the southern Lowlands. The highlanders were of the Celtic race and culture, were affiliated to groups called clans with names like Macgregor and Mackintosh.  Gaelic is one of the languages of the Celts. Highlanders mainly adhered to the Roman Catholic religion.  The Lowlanders were of the Anglo-Saxon race and were mostly Presbyterian, an austere form of the Protestant religion.

History of Scots-Irish Immigration to America in the 1600's: The "Ulster Plantation"
Rebellion in Ireland led to King James I to establish a colony, a massive plantation, for English and Scottish Protestant settlers. In 1609 Irish Lands in the regions of Ulster, Antrim and Down were confiscated from Gaelic chiefs who were most resistant to English rule. The aim was to drive the Catholic Irish out and colonize the lands with British protestants. King James I envisaged a land of rebels replaced by loyal settlers. Over half a million acres of land was confiscated to be colonized by English-speaking, Protestant tenants. Over 200,000 Scottish Lowland Presbyterians were encouraged by the English government to migrate to Ulster as rent-paying tenants. These were the descendents of the Scots-Irish, often called the Orangemen.

History of Scots-Irish Immigration to America in the 1600's: The Linen Trade
The Scots-Irish Immigration to America was prompted by the Irish linen trade. In 1632 the Lord Deputy of Ireland established the Irish linen industry. Irish linen was imported duty free to the British colonies in America. Scots-Irish Immigration to America was established via the linen trade ships. The first Scots-Irish settled in Philadelphia, the main destination port of the linen trade route, and introduced Scots-Irish immigrants to America, mainly because the linen trade routes were already well established. The Scots-Irish introduced flax growing and the production of linen to America.

History of Scots-Irish Immigration to America in the 1700's: Scots-Irish settle in America
The Scots-Irish Immigration to America increased. The Scots-Irish hated living under British rule and turned to the cheap lands and freedom of America. They were welcomed as migrants as they shared the same religion, culture and language of the British colonists. The Scots-Irish moved to destinations such as New England, the Ohio Valley, the Carolinas and Georgia. Many other Scots-Irish immigrants headed for the Appalachian regions - the Backcountry.

History of Scots-Irish Immigration to America in the 1700's: The 'Backcountry' Settlers
The largest proportion of the early Irish Immigration to America in the 1700's consisted of "Scots-Irish" settlers. In 1745, Colonel James Patten from Donegal, Ireland, obtained a grant of 120,000 acres in the 'Backcountry' that covered the Blue Ridge mountains and the Appalachian regions.  Colonel Patten sold plots of land to other Scots-Irish settlers who left Ireland, tired of the tyranny of British rule, high rents and crop failures.

History of Scots-Irish Immigration to America in the 1700's: The Indian Wars of the 1700's
Scots-Irish Immigration to America was hard and sometime dangerous for those who settled the frontier lands of Pennsylvania and western Virginia. Due to their close proximaty the Scots-Irish migrants became embroiled in wars with the Native American Indians during the mid 1700's These wars included the French and Indian Wars (1754–1763) and Pontiac’s Rebellion (1763–1766).

Scots-Irish Immigration to America in the 1700's: The Mecklenburg Declaration of Independence
Mecklenburg County in North Carolina had a large Scots-Irish population. It is claimed that Mecklenburg in North Carolina was to make the first of the 13 colonies to declare their independence from Great Britain. The Mecklenburg Resolves were a set of resolutions were passed after hearing of the battle of Lexington on May 31, 1775 at the beginning of the War of Independence.

Scotch-Irish Immigration to America in the 1700's: The War of Independence
The Scots-Irish Immigration to America played a significant role during the American War of Independence (1775–1783) as men fought fervently against British tyranny and for their freedom and justice. At the time of the American Revolution, at least one out of every 15 Americans was Scots-Irish. Eight Irish Americans were amongst those who signed the most important foundational document of the United States - the Declaration of Independence. Several signers were of Scots-Irish descent including Thomas McKean, George Taylor and James Smith  of Pennsylvania, Matthew Thornton a signatory from New Hampshire and Edward Rutledge a signatory from South Carolina.

Scotch-Irish Immigration to America in the 1700's: The Whiskey Rebellion
Scots-Irish Immigration to America played a part in another type of rebellion in 1791 - the Whiskey Rebellion. The US government had passed an excise tax in March 1791 on domestically distilled spirits (liquor). The government set up a system of local tax inspectors and collection officers to collect the tax. The new law particularly effected the Scots-Irish farmers of western Carolina and Pennsylvania who refused to pay the tax collectors - their action came to be called the Whiskey Rebellion.

Scots-Irish Immigration to America in the 1800's: The Pioneering Spirit
Following the War of Independence the 1893 Treaty of Paris established the first U.S. boundaries. The adventurous and pioneering spirit of the Scots-Irish witnessed their movement during the period of westward expansion into the new territories such as Louisiana, Florida, California, Tennessee and Texas. The famous American pioneer Davy Crocket was of Scots-Irish descent.

Scots-Irish Immigration to America in the 1800's: The Industrialization of America
Between 1720 and 1800 Scots-Irish Immigration to America had risen to more than 250,000. By the 1800's Scots-Irish Immigration to America was well established and their descendents were located across the whole of the emerging nation. Another famous man emerged of Scots-Irish descent when in 1829, Andrew Jackson, an Ulsterman, became the "people's President". Fifteen American presidents including James Madison, James Buchanan and Chester Arthur have claimed Scots-Irish descent. The 1800's saw the Industrialization of America and Scot-Irish also became pioneers of iron and steel including Thomas Mellon, Andrew Carnegie, James O'Hara and Isaac Craig. Pittsburgh became an important center of the Scots-Irish and many of its leaders, and those of other industrialized cities became "Captains of Industry".

Scots-Irish Immigration to America
The major waves of Scots-Irish Immigration to America occurred during the 1700's. Scots-Irish were accepted in United States as "old immigrants". In the US Census of 2000, 4.3 million Americans claimed Scotch-Irish ancestry, equivalent to 1.5% of the population of the United States.

Scots-Irish Immigration to America Facts Sheet and Timeline for kids
Important facts about the history of Scots-Irish Immigration to America and US laws that effected the migrants from Scotland are contained in the following Facts Sheet and history timeline.

Scots-Irish Immigration to America Facts Sheet and Timeline for kids

Fact 1: 1609: Presbyterian Protestants from the lowlands of Scotland emigrate to the "Ulster Plantation"

Fact 2: 1632: The Irish linen industry was established and Scots-Irish traveled to America on the linen trade ships

Fact 3: 1745: Colonel James Patten was granted land in the 'Backcountry' and sold plots to other Scots-Irish settlers

Fact 4: 1754: Scots-Irish migrants involved in the French and Indian War (1754–1763)

Fact 5: 1763: Scots-Irish migrants involved in the Indian war known as Pontiac’s Rebellion (1763–1766).

Fact 6: 1775: The Mecklenburg Declaration of Independence id proclaimed in Mecklenburg County, North Carolina

Fact 7: 1775: Scots-Irish patriots fight in the American War of Independence (1775–1783)

Fact 8: 1783: The Declaration of Independence includes Scots-Irish signers

Fact 9: 1791: The Whiskey Rebellion against liquor tax in Carolina and Pennsylvania

Fact 10: 1800's: Migrants move west across the country during the period of Westward expansion

Fact 11: 1800's: The Industrial revolution and enterprising migrants become leaders of the iron and steel industries

Scots-Irish Immigration to America Facts Sheet and Timeline

Push and Pull Factors of Scots-Irish Immigration to America for kids
For specific examples and a list of political, economic, environmental and social reasons and push and pull factors of Scots-Irish Immigration to America refer to:

Push and Pull Factors of Scots-Irish Immigration