Good morning, welcome to 3M's 2015 annual meeting in Austin, Texas. Every year, we open 3M's annual meeting with a tribute to our servicemen and women, and today we have six 3Mers that are remaining on active duty, serving the country with honor. To all our former and current military personnel, we salute your service, and thank you for your contribution to freedom and to 3M. I'd like to introduce Gregg Larson, 3M's corporate secretary. Gregg advises me that a quorum is present and that all shareholders of record have been sent a notice of this meeting. On the record date of March 13, 2015, there were approximately a proxy] . I declare this meeting open for business. Today, we will elect our board of directors, ratify the appointment of 3M's independent public accounting firm for 2015, and take an advisory vote on executive compensation.
As always, if there's any questions, we will of course take them. First, I'd like to talk about our performance since our last annual meeting. It has been a period of growth and progress. Our accomplishments are reflected in our 2014 results. The full year, as well as in its each individual quarter, we posted organic growth across all business groups and all geographic areas. In 2014, sales were an all-time high of $31.8 billion. Operating income increased to $7.1 billion, and we expanded margins to 22.4%. We also made good progress on each of our long-term financial objectives. Earnings per share rose 11.5% to $7.49. Organic growth was 4.9%. Return on invested capital was 22%, and we continued to generate strong cash flow with a conversion rate of 104%. In 2014, we returned $7.9 billion in cash to shareholders through dividends and share repurchases.
3M has paid dividends without interruption for 98 years, and we recently announced a 20% increase in the 2015 dividend, which came on top of a 35% increase last year. I hope you agree with me that 2014 was a very strong year for 3M, and I would like to take this opportunity to thank all 3M people around the world for their contributions to our 2014 results. I'd like to give you an update on how 2015 is shaping up. In the first quarter, 3M executed well and delivered another solid operational performance. We once again posted broad-based organic sales growth and improved profitability. Our team delivered sales of $7.6 billion, with positive organic growth in all business groups and all geographic areas for the seventh consecutive quarter. We grew organic sales by 3.3%. At the same time, the stronger U.S. dollar reduced quarterly sales by 6.5%.
Sales were down 3.2% versus last year. Earnings in the quarter were $1.85 per share, up 3.4% year-over-year. We expanded margins to 22.8%, up nearly a full percentage point from last year. All business groups delivered margins greater than 21%. In the quarter, we returned $1.5 billion to shareholders through dividends and share repurchases. As I said earlier, we increased our first quarter dividend by 20%. As we do business around the world, we always have one eye on the microscope and the other eye on the telescope. The microscope view is to make sure we deliver results quarter by quarter. The telescope view is to make sure we are investing for the long-term success of our enterprise. Three strategic levers are essential for our future. The first one is portfolio management. At 3M, we constantly challenge ourselves to strengthen our competitive position.
Since 2012, we have realigned from 6 sectors to 5 business groups and from 40 businesses to 27. These actions are delivering significant benefits, including greater customer relevance, scale, and productivity. We also look to enhance our portfolio and complement organic growth through mergers and acquisitions. In 2014, we invested $1 billion in acquisitions, including the remaining 25% of our Japanese subsidiary, and we initiated the sale of our static control business, which closed in January of this year. Recently, we announced plans for another $1 billion acquisition that will enhance our core filtration platform. Our primary strategy is organic local currency growth, as reflected in our second lever, invest in innovation. The research and development is the heartbeat of 3M. Our 46 technology platforms are owned by the enterprise and shared across all businesses in the company in order to provide cost-effective, innovative solutions for our customers globally.
I'm absolutely committed to provide the resources needed to accelerate organic growth in a productive way. In other words, efficient growth. We invested $1.8 billion in research and development in 2014, making our total investment $8.1 billion in the past five years. Our focus is on disruptive technologies and extending core platforms. As evidence of our long-term commitment to research and development, we received our 100,000th patent in 2014. Sustainability also remains a core value for 3M in our own operations and in the products we invent. We continue to invest in developing more sustainable products to help our customers reach their environmental goals. This is our part to help protect the planet while growing our business. Our third lever is business transformation, which will make us more agile, more efficient, and most importantly, more responsive to our customers.
The backbone of our efforts is a new enterprise resource planning system. We're making good progress, including a successful deployment in our largest European distribution center. Supporting each of these levers are the skills and determination of our people. Because of the engagement of our global team, the state of our enterprise is strong, and the future is even brighter. Going forward, like always, we will continue to drive by both innovation and integrity. Our code of conduct is clear and easy to understand. Be good, be honest, be fair and impartial, be loyal, be accurate, and be respectful. Our code defends who we are and will continue to be the foundation of our success. That concludes my morning report, and now I would like to introduce the board of directors.
I will ask each director to stand as they're introduced, I please ask you to hold your applause till everyone are introduced. Linda Alvarado, President and Chief Executive Officer, Alvarado Construction. Sondra Barbour, Executive Vice President, Information Systems and Global Solutions, Lockheed Martin Corporation. Tony Brown, retired Group Vice President, Global Purchasing, Ford Motor Company. Dr. Vance Coffman, retired Chairman of the Board and Chief Executive Officer, Lockheed Martin Corporation. Mike Eskew, retired Chairman of the Board and Chief Executive Officer, United Parcel. Herb Henkel, retired Chairman of the Board and Chief Executive Officer, Ingersoll Rand. Muhtar Kent, Chairman of the Board and Chief Executive Officer, The Coca-Cola Company. Ed Liddy, retired Chairman of the Board and Chief Executive Officer of The Allstate Corporation, and now partner, Clayton, Dubilier & Rice. Finally, Bob Ulrich, retired Chairman of the Board and Chief Executive Officer, Target Corporation.
Well, thank you, Inge. Good morning, everyone. Before discussing the business items, please review the meeting rules that you received this morning. They are summarized on the screen behind me. 3M has these rules to better accommodate the shareholders who attend this meeting and to be fair to everyone who wishes to speak. Your cooperation is greatly appreciated. As indicated on the agenda you also received, the board of directors is presenting the following proposals, which are described in the proxy statement. Elect the 10 directors identified in the proxy statement, ratify the appointment of PricewaterhouseCoopers as 3M's independent registered public accounting firm for 2015, and consider an advisory approval of executive compensation. We will vote on all of these proposals together after presenting each one. No other items of business will be considered at the meeting.
The board appointed three inspectors of election for this meeting who are with us this morning. They are Tony Corridio, Matt Criscenzo, and Jan Dreiman. They are independent of 3M and agents of Broadridge Financial Solutions. The first proposal is to elect 10 directors for a one-year term that expires at the 2016 annual meeting. The board's nominees are Linda Alvarado, Sondra Barbour , Tony Brown, Dr. Vance Coffman, Mike Eskew, Herb Henkel, Muhtar Kent, Ed Liddy, Inge Thulin, and Bob Ulrich. All nominees are standing for re-election to the board, except Sondra Barbour , who is standing for election to the board for the first time. The second proposal is to ratify the appointment of PricewaterhouseCoopers as 3M's independent registered public accounting firm. The audit committee appointed PricewaterhouseCoopers to audit the 2015 consolidated financial statements of 3M and its subsidiaries.
Tom Montminy , the lead partner from PricewaterhouseCoopers, is here at the meeting. The third proposal is to approve the compensation of our executives as described in the proxy statement. While the vote on this proposal is non-binding, the compensation committee and the board will carefully consider the outcome of the vote when making future compensation decisions. The board recommends an affirmative vote for each nominee and for each of these proposals. We are finished presenting the items of business in the proxy statement, and now it is time to vote. If you submitted your proxy over the internet, by telephone or by mail, it will be voted as you instructed. Please ask for a ballot only if you did not previously vote or if you wish to change your vote. If you need a ballot, please stand and an attendant will give you a ballot.
When you have marked your ballots, please stand and the attendants will collect them. The polls are about to close. If there is any shareholder who has not turned in a ballot and wishes to do so at this time, please stand so that the attendants can pick up your ballot. The polls are now closed. The preliminary results of the voting will be announced later in the meeting. This concludes the business segment of the meeting and our live webcast. Now I would like to turn the program back to our chairman.