Sikhs migrated in small numbers to the West in the last years of the 19th century and the early 20th century. Mass scale immigration to Great Britain occurred after World War II, when men were needed to run British industries. Having a strong work ethic, Sikhs made a good living and invited their relatives to settle there. Now, Sikhs are playing a significant role in British social, political, and economic fields. The children of immigrant Sikhs are well established in various professional fields. They have proven themselves as top-class doctors, engineers, industrialists, and businessmen.

Sikhs also spread extensively throughout southeast Asia, and some Sikhs reached as far as Africa. Early visitors to North America settled primarily on the Pacific coast, in California, USA, and British Columbia, Canada. They established Gurdwaras in Stockton, Vancouver, and other cities. They faced stiff resistance to their presence.

During those days, the United States refused to grant citizenship to anyone who was not white. In a landmark Supreme Court case, United States vs. Bhagat Singh Thind, the Supreme Court ruled that Bhagat Singh could not become a naturalized citizen even though anthropologists had defined him as a member of the Caucasian race. According to the U.S. Supreme Court, Bhagat Singh, despite technically being Caucasian, was not a white person as used in "common speech, to be interpreted in accordance with the understanding of the common man".

The opinion, written by Associate Justice George Sutherland, found that while Bhagat Singh was technically Caucasian, "the average man knows perfectly well that there are unmistakable and profound differences", so he was denied citizenship.

There are several facts which make the above ruling shocking, three of which will be mentioned here. First, Bhagat Singh Thind was a World War I combat veteran in the United States Army. Apparently this was not important enough for him to be granted citizenship. Second, the same Court had ruled previously in United States vs. Takao Ozawa that Mr. Ozawa could not become an American citizen, even though he was indistinguishable from whites in appearance and mannerisms, because technically he was not Caucasian. Hence, many people felt that the Court had contradicted itself in the two cases with opposite rulings. Third, this ruling allowed the retroactive stripping of citizenship from Sikhs who were already Americans. Many Sikhs were forced to leave their country and their land was seized.

The above interpretation of the law remained in effect until July 2, 1946, when President Truman signed the Luce-Celler Act, which reversed the Thind decision. This opened the door to Sikh immigration, and after further restrictive laws were reversed, tens of thousands of Sikhs took advantage of the opportunity to become American citizens.

Sikhs faced similar problems in Canada. Laws there were equally harsh. Sikhs were not allowed to marry, to become professionals such as doctors or lawyers, or even to travel on interstate highways. Anti-Asiatic rioters stoned Sikh businesses and assaulted Sikhs. Permits for the building of Gurdwaras, the cornerstones of Sikh life, were made as difficult to obtain as possible. But ultimately, after a long and hard struggle, these laws too came tumbling down.

One of the most instrumental Sikh leaders in reversing this discrimination was Teja Singh, who later was to become Professor Sant Teja Singh of Mastuana. He was a graduate of Harvard University (which initially tried to block his enrollment) and president of the Pacific Coast Society of Sikhs. He explained Sikhism to the Canadian religious leaders, politicians, and other members of society who resented the Sikh presence. He told them that Sikhism is a faith for all humanity, and that Sikhs were hardworking, loyal, and deserving people. This made a huge impact in turning public opinion in favor of the Sikhs.

Today, it is estimated there are over a million Sikhs in Britain, Canada, the United States, and other European countries. Sikh leaders like Sant Teja Singh Ji had the maturity to understand that every person immigrating to a new social, cultural, or geographic environment will face problems, and thus they took steps to educate the local populace, promote strong citizenship, and ultimately, earn the goodwill and trust of those who once resented them.

Visionary leaders foretold the potential of Sikhism in Western countries, and now those predictions are coming true. A Sikh served in the United States Congress, a Sikh was appointed to the Canadian Supreme Court, Sikhs have become prominent elected politicians in both Canada and Great Britain, and now, a Sikh has become the Prime Minister of India.

In addition, Sikhs have begun to develop extensive community support networks in their newly adopted Western countries. There are now Sikh lobbyists to the United States Congress, Sikh newspapers and media outlets, Sikh support and civil rights groups, and more. These trends should continue and escalate. Sikhism has gone global, both geographically and in mindset.