It is unique among East Chicago neighborhoods for its suburban character, including a curvilinear street grid.

[1] The neighborhood was built over the first half of the 20th century by Inland Steel as employee housing.

[2] Another 100 units were built in the 1940s in response to the post-World War II housing shortage.

[2] Inland Steel retained ownership, renting the homes to employees, until 1969 when it began selling them off.

[2] Notable people from Sunnyside include basketball coach Gregg Popovich[4] and venture capitalist Tim Draper.