By the late 19th century, rice, pepper, sago, coffee, gambier, and cassava had become important products of the Selangor plains. The Chinese began engaging in plantation agriculture in 1870 when Yap Ah Loy established a gambier plantation in Kuala Lumpur. He also planted gambier near Sungai Way in Petaling. In 1884, the British colonial government enacted specific regulations to encourage the cultivation of gambier and pepper in Negeri Sembilan, Perak, and Selangor. Consequently, gambier and pepper plantations of various sizes emerged in Kuala Langat, Kuala Lumpur, and Ulu Langat. In 1903, as the prices of gambier and pepper fell while rubber prices surged, gambier and pepper gradually disappeared. Coffee prices also dropped, and pest infestations led many plantation owners to switch to rubber cultivation.

Tin mining only gradually became the economic lifeline of Selangor in the mid-19th century, with most tin mining areas concentrated in the eastern half. Towns such as Kuala Lumpur, Ampang, Sungei Buloh, Kajang, Simpang Lima, Beranang, and Serdang were developed due to mining activities. The growth of the tin mining industry also stimulated the demand for food cultivation and commercial activities, causing small settlements to gradually expand into towns and cities.

Lukut was the earliest developed mining area in Selangor, predominantly populated by Hakka miners. Subsequent mining areas in Kanching and Kuala Lumpur were also developed by the Hakka community. These regional ties significantly contributed to the economic expansion of Selangor. Another reason for the concentration of Hakka people in Selangor was that the major tin mining areas in Perak, the largest tin-producing state in Malaya, had already been occupied by Cantonese and Teochew people. Consequently, the Hakka had to explore later-developing areas like Selangor for mining opportunities, establishing many mining settlements there.

The development of mining areas provided employment opportunities for Chinese immigrants, leading to a population surge in these settlements. By the late 19th century, the Chinese population in Selangor was mainly concentrated in these mining areas. These mining areas were primarily controlled by a few large mining magnates. For example, Yap Ah Loy, the largest tin miner in Selangor, owned over 1,000 acres of mining land in the state by 1882. The development of areas such as Ampang, Petaling, Kepong, Kuala Kubu, Pudu, and Sungei Buloh was directly or indirectly related to his tin mining activities. Other prominent mining magnates of the time included Yap Chit Ying, Yap Kwan Seng, Cheow Yoke, and Loke Yew.

The prosperity of the tin mining industry also spurred agricultural development. Before the rise of the tin mining industry, the demand for agricultural products in Selangor was low. However, as mining areas developed, miners were too occupied with mining activities to grow their own food, necessitating the provision of daily rice supplies by nearby villages. Thus, the agricultural land around the mining areas rapidly expanded with the development of the mines and the increase in the resident population.

In 1911, among the Chinese community in Selangor, Hakka and Cantonese people were the predominant groups, with Hokkien people ranking third. However, their proportion had surged from 8.6% a decade earlier to 18.41%. The fluctuations in the proportion of various dialect groups were influenced by specific factors at the time.

At the beginning of the 20th century, the tin mining industry in Selangor was largely controlled by several prominent Cantonese mining magnates, such as Chen Xiulian, Chen Zhanmei, and the Loke brothers. Chen Xiulian and Loke Yew were appointed as members of the state council and transferred part of the lease contracts to Cantonese people, attracting more Cantonese to Kuala Lumpur. The origin of employers influenced the formation of community boundaries in the industry. By the early 20th century, Cantonese people had replaced Hakka people as the leading group in the tin mining industry in Selangor.

By the end of the 19th century, inland towns developed in the mining areas were predominantly populated by Hakka and Cantonese people. Coastal towns from Sepang to Tanjong Sepat were the most concentrated areas for Hokkien people, especially in Klang, where they accounted for more than half of the population. The significant increase in the Hokkien population in Selangor from 8.6% to 18.41% within 20 years was primarily due to the rise of the plantation industry.

By the time of World War II, there had been significant changes in the structure of the Chinese community in Selangor. In 1931, the Hokkien population had grown to 67,405, surpassing the Cantonese and becoming the second-largest dialect group. The Hakka population remained the largest, reaching 80,167. However, after World War II, the Hokkien population surged to 113,123, making them the largest dialect group in Selangor.

The number of Hokkien people in Selangor was only 5,367 in 1891 but surged to 32,174 in 1911, and further rose to 67,405 in 1931, and peaked at 113,123 in 1947 after World War II. Selangor developed alongside the tin mining industry, dominated by Cantonese and Hakka dialect groups. After the influx of Hokkien people, they could only engage in small businesses in urban areas or endure hardships in the suburbs, contributing to the development of rubber plantations. This subsequently led to the Hokkien people’s dominance in the rubber and commercial sectors. Coastal towns in Selangor were mostly developed due to plantation activities. Areas with concentrated Hokkien communities, such as Sungai Buloh, Ijok, Batang Berjuntai, Rawang, Serendah, Tanjung Sepat, and Sungai Pelek, developed rapidly in the early 20th century due to the prosperity of the plantation industry.

The Selangor Hokkien Association was established in Kuala Lumpur in 1885. Although the number of Hokkiens in Kuala Lumpur County and Kuala Lumpur City was only over 4,000 in 1891, the establishment of the Selangor Hokkien Association indicated a high level of cohesion among Hokkien people at that time. Engchoon people, who were only the third-largest dialect group within the Hokkien community before World War II, began establishing networks in the rubber industry, particularly during the early 20th century when rubber business flourished, solidifying their social status within the Chinese community in Kuala Lumpur.