One hundred holidays ago, a 29-year-old Connecticut man brought a product to market that would become an American icon and redefine the holiday season. As a train passenger, 1909 Yale graduate Alfred Carlton Gilbert had watched the steel tower construction to electrify the New Haven Railroad\u2019s access to the new Grand Central Terminal. At the time, steel and electricity were reinventing America. Gilbert\u2019s Erector Set of metal nuts, bolts and small motors captured that spirit. A century later, the Eli Whitney Museum in Hamden will mark the toy\u2019s milestone with \u201cThe Erector Set at 100\u201d exhibit and celebration. Timeline, advertising and many pieces The exhibition features a timeline of the Erector Set\u2019s evolution and connections to major events of the 20th century. There are Erector Sets with familiar and unfamiliar pieces, and samples of advertising that show Gilbert as one of the early masters of brand management. There are motors, pulleys and gears. Visitors can try their hand at mastering movement. There are nuts and bolts and girders for visitors to construct a Gilbert box girder to contribute to a skyscraper that will climb 25 feet over the course of the exhibition. \u201cThere is a practical beauty in this toy that still works a half-century past its most glorious days,\u201d said museum officials. \u2018Hello Boys\u2019 advertising slogan The toy was marketed by the A.C. Gilbert Co., with its famous slogan of \u201cHello Boys.\u201d The Erector Set was one of the country\u2019s biggest-selling toys from its invention into the 1950s. Today, some older sets are heavily sought after by toy collectors. Its success raises some interesting questions: Can a toy be a learning tool? Can tinkering change the way we think? Can advertising persuade a society to invest in play? Can an expensive toy be a popular toy? Are there boys\u2019 toys and girls\u2019 toys? Is toy safety overrated? Exhibit runs Nov. 29-Jan. 26 \u201cThe Erector Set at 100\u201d exhibit joins Albert C. Gilbert\u2019s model railroad and the Eli Whitney Museum\u2019s annual American Flyer train exhibition, during the holiday season. The Erector Set exhibit is supported by a grant from the Connecticut Humanities as part of its year-long Connecticut at Work initiative. The exhibit opens on Nov. 29 and will run through Jan. 26. The Eli Whitney Museum and Workshop is at 915 Whitney Ave., Hamden. Regular museum hours are Saturday from 10 a.m.-3 p.m., and Sunday from noon-5 p.m. The museum also will be open Friday, Nov. 29 from noon-5 p.m., and have special hours during Christmas week. Admission is free with donations accepted. Learn more at www.eliwhitney.org.