Investing for the long term is proven to be a winning strategy, but there's something else that increases investors' odds: large-capitalization stocks. The fact of the matter is that businesses sporting multibillion-dollar valuations are often built to last and are therefore capable of rewarding shareholders for the long term. 

With this insight in mind, we asked some of The Motley Fool's top contributors for their best long-term investment ideas in the large-capitalization space. In reply, they offered up Macy's (M -2.02%), AT&T (T -0.09%), and McCormick (MKC 0.27%)

Read on for all the key details.

A stock chart moving up through time.

Image source: Getty Images.

A department store on sale

Sean O'Reilly (Macy's):  Readers (and investors) have no doubt strolled through a Macy's store. They are also, no doubt, aware of the widespread malaise afflicting the retail sector. Needless to say, times have been less than ideal for the department-store retailer. For its fiscal first quarter, ended April 2017, Macy's reported adjusted earnings per share of $0.24, down from $0.40 a year earlier. Adding insult to injury, it posted net sales of $5.3 billion, down 7.5% from a year earlier. Worse, comparable-store sales dipped 5.2%, while comparable-store sales at locations owned and co-owned fell 4.6%. Fortunately, thanks to store closures, sound fiscal discipline, and investments in e-commerce, the future appears bright.

Macy's online sales increased by double digits year over year -- the highlight of its first-quarter conference call. Unsurprisingly, Macy's is expanding on the internet, and its efforts are starting to pay off as shown by the double-digit growth of digital sales in Q1 2017. In addition to reinvesting in the future, Macy's continues to return value to shareholders. In 2016, Macy's repurchased 7.9 million shares while simultaneously increasing its dividend by 5% in that same year.

Given its incredibly low valuation, laudable dividend yield, and dominant position in the department-store space, Macy's is a compelling choice for any long-term investor.

How to play the growth in connected devices

Travis Hoium (AT&T): Cell phones are ubiquitous, and AT&T has one of best networks in an industry with extremely high barriers to entry. That gives a profitable foundation from which to build, and the acquisition of DIRECTV gives AT&T the opportunity to bundle wireless with next-generation digital TV offerings. 

The wireless and digital-cable business may not be growing today, but I think that's about to change. As devices like cars, smart-home components, wearables, and other connected devices become more commonplace, they'll need to connect to a wireless network to function. AT&T has one of the top networks and can develop the partnerships required to connect devices quickly and efficiently. 

Long-term, I think the market's trends are favorable for AT&T, and the company's growth will surge as more and more devices come online. And it should be able to generate some renewed excitement as it rolls out its 5G network. But in the meantime, the company's 5.1% dividend yield is a nice payout for investors. And with the stock trading at under 19 times earnings, the current price isn't bad either.

Slow and steady wins the race

Brian Feroldi (McCormick): Nearly every grocery store in America has a spice aisle that is dominated by one company -- McCormick. This century-old business has been lighting up consumer's taste buds for years and will likely be doing more of the same a few decades from now.

Selling spices might sound like a humdrum business, but the economics are quite compelling. That's because spices are cheap and yet they are essential to making food taste great. Those factors allow McCormick to pass along regular price increases and, combined with a few tuck-in acquisitions and steady margin improvements, result in revenue and profit growth that are highly predictable.

MKC Revenue (TTM) Chart

MKC Revenue (TTM) data by YCharts.

Looking ahead, McCormick has several trends working in its favor. Consumers worldwide are growing wealthier, which should steadily increase the demand for better-tasting food. Indeed, the company is undergoing a steady expansion into new geographies. People are also increasingly willing to dine out, which benefits the company since all of the top 10 restaurant chains are McCormick customers. McCormick looks well positioned for growth.

All in all, McCormick boasts all of the traits of a "Steady Eddy" business that conservative investors love to see. With shares down about 8% from their recent high, I think right now is an excellent time to consider getting in.